This is a working overview of Ac-SDKP, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2025-10-31. Anything still debated is marked as such rather than presented as settled.
The fragment most often associated with the name carries the sequence Ac-LKKTETQ, matching residues 17 through 23 of thymosin beta-4. That region holds the actin-binding motif responsible for much of the parent protein's biochemical activity. Apart from N-terminal acetylation the peptide is unmodified and contains no disulfide bonds, so it shows little ordered secondary structure in solution. Full-length thymosin beta-4 is instead a 43-residue polypeptide of roughly 4.9 kDa found widely across mammalian cell types.
Material sold under this label typically arrives as a freeze-dried powder in a sealed vial with a certificate of analysis. Such certificates usually report reversed-phase chromatography purity plus a mass confirmation, and stated purities commonly sit between 95 and 99 percent. Counter-ion identity, residual trifluoroacetate, water content, and peptide net weight are separate specifications that a certificate may or may not include. A purity figure alone does not establish sequence identity, so independent mass verification remains the practical check.
Research interest in thymosin beta-4 fragments centres on actin sequestration, cell migration and tissue repair models. Most published work uses cultured cells or animal wound and cardiac preparations, and findings are generally described as preliminary. No fragment of this protein has been approved as a therapeutic product by major regulators. Reviews of the field note inconsistent dosing, delivery routes and outcome measures across studies, which complicates direct comparison. The material is best understood as a laboratory reagent with an active but unresolved research literature.
TB-500 is a catalogue name applied to a synthetic peptide related to thymosin beta-4, an actin-binding protein found in most mammalian cells. Suppliers do not use the label consistently: some describe it as the full 43-residue protein, others as a short fragment from the actin-binding region, and others as a related tetrapeptide. Because the name is commercial rather than chemical, two products sold under it may not contain the same molecule. This naming ambiguity is the first point to check in any description of the material.
| Property | Value | Notes |
|---|---|---|
| Molecular mass | ≈889 Da for the 7-residue fragment | Full-length thymosin beta-4 is ≈4.9 kDa; catalogs differ |
| Appearance | White to off-white powder | Hygroscopic; weight shifts with residual moisture |
| Solubility class | Freely soluble in water | Also dissolves in aqueous buffers; poorly soluble in nonpolar solvents |
| Typical storage temperature | −20 °C, desiccated, protected from light | Once rehydrated, short-term holding at 2-8 °C |
| Typical analytical method | Reversed-phase HPLC with mass spectrometry | Purity by UV absorbance; identity by ESI-MS or MALDI-TOF |
Identity and purity are assessed with a small set of standard techniques. Reverse-phase high-performance liquid chromatography gives a purity estimate from peak area, usually recorded at 214 or 220 nanometers, where the peptide bond absorbs. Mass spectrometry confirms the expected molecular mass and can reveal truncated or oxidized species. Amino acid analysis or tandem mass spectrometry sequencing can verify the sequence itself. Additional quality attributes include water content, residual trifluoroacetic acid carried over from purification, and endotoxin where the material is intended for biological work.
The compound is most often distributed as a lyophilized powder, appearing white to off-white and forming a loose cake or fluffy solid. It is hygroscopic to some degree, so brief exposure to humid air can add water weight and complicate weighing. The peptide dissolves readily in water and in neutral aqueous buffers, and aqueous solubility is generally described as high, well above the concentrations used in typical assays. Some polar organic solvents are also usable, which matters when a concentrated stock is prepared before dilution into buffer.
Detection in biological samples relies on mass spectrometry, typically liquid chromatography coupled to tandem mass spectrometry after peptide extraction and enrichment. Intact peptides can also be confirmed by high-resolution mass measurement together with fragmentation data. Detection windows in urine are short because the peptide is degraded by proteases and cleared quickly, and concentrations are low. Many jurisdictions treat the compound as a prohibited substance in sport, grouped with peptide hormones and related factors, while it is not an approved therapeutic product. Identity and purity statements therefore rest on certificates of analysis, ideally issued by an independent laboratory.
Material is normally supplied as a lyophilised powder in a sealed vial. The powder is hygroscopic, so exposure to humid air leads to water uptake, caking and gradual loss of the fluffy texture that indicates a good freeze-dry. Vials are best kept sealed with desiccant, protected from light and stored cold. Letting a cold vial warm to room temperature before opening reduces condensation on the contents. Purity is normally reported from a chromatographic run, and that figure applies to the batch as tested rather than to the vial after repeated opening.
Once dissolved, the peptide is far less stable than the dry powder. Aqueous solutions are subject to hydrolysis, oxidation at susceptible residues and gradual loss of material through adsorption onto glass and plastic surfaces. Terminal glutamine can cyclise under some conditions, producing a related species that complicates purity assessment. Dilute solutions tend to lose a larger fraction of material to surfaces than concentrated ones. Buffers, pH and ionic strength all influence the rate of change, so stability figures are only meaningful when those parameters are stated alongside the storage interval.
Full-length thymosin beta-4 consists of roughly forty-three amino acids and ranks among the more abundant small proteins in the cytoplasm. The fragment is much shorter, so it cannot reproduce every function attributed to the intact molecule. In cell culture, short actin-binding motifs can interfere with filament dynamics and cell movement, but such observations come from controlled experiments rather than from whole-animal work. Whether a truncated fragment produces the same effects as the parent protein remains an open question.
Interest in the peptide grew during the 2000s and 2010s, when studies of tendon and ligament injuries in horses reported changes in lesion size after treatment. Those reports circulated widely outside the scientific literature and shaped much of the current online discussion. Subsequent reviews noted inconsistent study design, small groups, and a shortage of independent replication. Popular descriptions often blur the line between the fragment, the complete protein, and unrelated growth factors, which complicates comparisons across sources.
TB-500 is a synthetic peptide whose sequence corresponds to a short fragment near the N-terminus of thymosin beta-4, a small protein present in most mammalian cells. The fragment is commonly cited as containing the actin-binding region of the parent molecule, which is why it appears in laboratory work on cell migration and tissue repair. Suppliers distribute it as a lyophilised powder intended for research use. Its identity is defined by amino acid sequence and by the presence of an acetyl group on the N-terminal residue.
Baptized Sikhs are specifically instructed to have unshorn Kesh (the hair on their head and beards for men) as a major tenet of the Sikh faith. To Sikhs, the maintenance and management of long hair is a manifestation of one's piety. The majority of Muslims believe that adult removal of pubic and axillary hair, as a hygienic measure, is religiously beneficial. Under Muslim law (Sharia), it is recommended to keep the beard. A Muslim may trim or cut hair on the head. In the 9th century, the use of chemical depilatories for women was introduced by Ziryab in Al-Andalus.
An improvement on the loose-coupled train is the "Instanter" coupling, in which the middle link of a three-link chain is specially triangular shaped, so that when lying "prone" it provides enough slack to make coupling possible, but when the middle link is rotated 90 degrees, the length of the chain is effectively shortened, reducing the amount of slack without the need to wind a screw. The closeness of the coupling allows the use of inter-vehicle pipes for train brakes. Three-link and Instanter couplings can be operated entirely from the side of the wagons, using a shunter's pole, which has a hook on the end, and is safer when shunting is being done. Similarly, the screw-adjustable coupler can be connected by a shunter's pole once it has been unscrewed. Ordinary three-link couplings have been superseded by instanter, screw or buck-eye couplers in UK freight trains today.
Preparation begins with the heating of stones over a fire, and the meat is then placed on top. The fire is covered with grass and earth, and the resulting oven is opened up after around two hours. Typically, a large quantity of meat is cooked, perhaps a whole sheep, to serve several people.
=== EC 2.3.1: Transferring groups other than amino-acyl groups === EC 2.3.1.1: amino-acid N-acetyltransferase EC 2.3.1.2: imidazole N-acetyltransferase EC 2.3.1.3: glucosamine N-acetyltransferase EC 2.3.1.4: glucosamine-phosphate N-acetyltransferase EC 2.3.1.5: arylamine N-acetyltransferase EC 2.3.1.6: choline O-acetyltransferase EC 2.3.1.7: carnitine O-acetyltransferase EC 2.3.1.8: phosphate acetyltransferase EC 2.3.1.9: acetyl-CoA C-acetyltransferase EC 2.3.1.10: hydrogen-sulfide S-acetyltransferase EC 2.3.1.11: thioethanolamine S-acetyltransferase EC 2.3.1.12: dihydrolipoyllysine-residue acetyltransferase EC 2.3.1.13: glycine N-acyltransferase EC 2.3.1.14: glutamine N-phenylacetyltransferase EC 2.3.1.15: glycerol-3-phosphate O-acyltransferase EC 2.3.1.16: acetyl-CoA C-acyltransferase EC 2.3.1.17: aspartate N-acetyltransferase EC 2.3.1.18: galactoside O-acetyltransferase EC 2.3.1.19: phosphate butyryltransferase EC 2.3.1.20: diacylglycerol O-acyltransferase EC 2.3.1.21: carnitine O-palmitoyltransferase EC 2.3.1.22: 2-acylglycerol O-acyltransferase EC 2.3.1.23: 1-acylglycerophosphocholine O-acyltransferase EC 2.3.1.24: sphingosine N-acyltransferase EC 2.3.1.25: plasmalogen synthase EC 2.3.1.26: sterol O-acyltransferase EC 2.3.1.27: cortisol O-acetyltransferase EC 2.3.1.28: chloramphenicol O-acetyltransferase EC 2.3.1.29: glycine C-acetyltransferase EC 2.3.1.30: serine O-acetyltransferase EC 2.3.1.31: homoserine O-acetyltransferase EC 2.3.1.32: lysine N-acetyltransferase EC 2.3.1.33: histidine N-acetyltransferase EC 2.3.1.34: D-tryptophan N-acetyltransferase EC 2.3.1.35: glutamate N-acetyltransferase EC 2.3.1.36: D-amino-acid N-acetyltransferase EC 2.3.1.37: 5-aminolevulinate synthase EC 2.3.1.38: [acyl-carrier-protein] S-acetyltransferase EC 2.3.1.39: [acyl-carrier-protein] S-malonyltransferase EC 2.3.1.40: acyl-[acyl-carrier-protein]—phospholipid O-acyltransferase EC 2.3.1.41: β-ketoacyl-[acyl-carrier-protein] synthase I EC 2.3.1.42: glycerone-phosphate O-acyltransferase EC 2.3.1.43: phosphatidylcholine—sterol O-acyltransferase EC 2.3.1.44: N-acetylneuraminate 4-O-acetyltransferase EC 2.3.1.45: N-acetylneuraminate 7-O(or 9-O)-acetyltransferase EC 2.3.1.46: homoserine O-succinyltransferase EC 2.3.1.47: 8-amino-7-oxononanoate synthase EC 2.3.1.48: histone acetyltransferase EC 2.3.1.49: deacetyl-(citrate-(pro-3S)-lyase) S-acetyltransferase EC 2.3.1.50: serine C-palmitoyltransferase EC 2.3.1.51: 1-acylglycerol-3-phosphate O-acyltransferase EC 2.3.1.52: 2-acylglycerol-3-phosphate O-acyltransferase EC 2.3.1.53: phenylalanine N-acetyltransferase EC 2.3.1.54: formate C-acetyltransferase EC 2.3.1.55: identical to EC 2.3.1.82 EC 2.3.1.56: aromatic-hydroxylamine O-acetyltransferase EC 2.3.1.57: diamine N-acetyltransferase EC 2.3.1.58: 2,3-diaminopropionate N-oxalyltransferase EC 2.3.1.59: gentamicin 2′-N-acetyltransferase EC 2.3.1.60: gentamicin 3′-N-acetyltransferase EC 2.3.1.61: dihydrolipoyllysine-residue succinyltransferase EC 2.3.1.62: 2-acylglycerophosphocholine O-acyltransferase EC 2.3.1.63: 1-alkylglycerophosphocholine O-acyltransferase EC 2.3.1.64: agmatine N4-coumaroyltransferase EC 2.3.1.65: bile acid-CoA:amino acid N-acyltransferase EC 2.3.1.66: leucine N-acetyltransferase EC 2.3.1.67: 1-alkylglycerophosphocholine O-acetyltransferase EC 2.3.1.68: glutamine N-acyltransferase EC 2.3.1.69: monoterpenol O-acetyltransferase EC 2.3.1.70: deleted EC 2.3.1.71: glycine N-benzoyltransferase EC 2.3.1.72: indoleacetylglucose—inositol O-acyltransferase EC 2.3.1.73: diacylglycerol—sterol O-acyltransferase EC 2.3.1.74: chalcone synthase EC 2.3.1.75: long-chain-alcohol O-fatty-acyltransferase EC 2.3.1.76: retinol O-fatty-acyltransferase EC 2.3.1.77: triacylglycerol—sterol O-acyltransferase EC 2.3.1.78: heparan-α-glucosaminide N-acetyltransferase EC 2.3.1.79: maltose O-acetyltransferase EC 2.3.1.80: cysteine-S-conjugate N-acetyltransferase EC 2.3.1.81: aminoglycoside 3-N-acetyltransferase EC 2.3.1.82: aminoglycoside 6′-N-acetyltransferase EC 2.3.1.83: phosphatidylcholine—dolichol O-acyltransferase EC 2.3.1.84: alcohol O-acetyltransferase EC 2.3.1.85: fatty-acid synthase system EC 2.3.1.86: fatty-acyl-CoA synthase system EC 2.3.1.87: aralkylamine N-acetyltransferase EC 2.3.1.88: Now covered by EC 2.3.1.254, EC 2.3.1.255, EC 2.3.1.256, EC 2.3.1.257, EC 2.3.1.258 and EC 2.3.1.259 EC 2.3.1.89: tetrahydrodipicolinate N-acetyltransferase EC 2.3.1.90: β-glucogallin O-galloyltransferase EC 2.3.1.91: sinapoylglucose—choline O-sinapoyltransferase EC 2.3.1.92: sinapoylglucose—malate O-sinapoyltransferase EC 2.3.1.93: 13-hydroxylupinine O-tigloyltransferase EC 2.3.1.94: 6-deoxyerythronolide-B synthase EC 2.3.1.95: trihydroxystilbene synthase EC 2.3.1.96: glycoprotein N-palmitoyltransferase EC 2.3.1.97: glycylpeptide N-tetradecanoyltransferase EC 2.3.1.98: chlorogenate—glucarate O-hydroxycinnamoyltransferase EC 2.3.1.99: quinate O-hydroxycinnamoyltransferase EC 2.3.1.100: [myelin-proteolipid] O-palmitoyltransferase EC 2.3.1.101: formylmethanofuran—tetrahydromethanopterin N-formyltransferase EC 2.3.1.102: N6-hydroxylysine O-acetyltransferase EC 2.3.1.103: sinapoylglucose—sinapoylglucose O-sinapoyltransferase EC 2.3.1.104: The activity is covered by EC 2.3.1.25 EC 2.3.1.105: alkylglycerophosphate 2-O-acetyltransferase EC 2.3.1.106: tartronate O-hydroxycinnamoyltransferase EC 2.3.1.107: deacetylvindoline O-acetyltransferase EC 2.3.1.108: α-tubulin N-acetyltransferase EC 2.3.1.109: arginine N-succinyltransferase EC 2.3.1.110: tyramine N-feruloyltransferase EC 2.3.1.111: mycocerosate synthase EC 2.3.1.112: D-tryptophan N-malonyltransferase EC 2.3.1.113: anthranilate N-malonyltransferase EC 2.3.1.114: 3,4-dichloroaniline N-malonyltransferase EC 2.3.1.115: isoflavone-7-O-β-glucoside 6′′-O-malonyltransferase EC 2.3.1.116: flavonol-3-O-β-glucoside O-malonyltransferase EC 2.3.1.117: 2,3,4,5-tetrahydropyridine-2,6-dicarboxylate N-succinyltransferase EC 2.3.1.118: N-hydroxyarylamine O-acetyltransferase EC 2.3.1.119: Now covered by EC 2.3.1.199, EC 1.1.1.330, EC 4.2.1.134 and EC 1.3.1.93 EC 2.3.1.120: The reaction is due to EC 2.3.1.74 EC 2.3.1.121: 1-alkenylglycerophosphoethanolamine O-acyltransferase EC 2.3.1.122: trehalose O-mycolyltransferase EC 2.3.1.123: dolichol O-acyltransferase EC 2.3.1.124: Already listed as EC 2.3.1.20 EC 2.3.1.125: 1-alkyl-2-acetylglycerol O-acyltransferase EC 2.3.1.126: isocitrate O-dihydroxycinnamoyltransferase EC 2.3.1.127: ornithine N-benzoyltransferase EC 2.3.1.128: now classified as EC 2.3.1.266 and EC 2.3.1.267 EC 2.3.1.129: acyl-[acyl-carrier-protein]—UDP-N-acetylglucosamine O-acyltransferase EC 2.3.1.130: galactarate O-hydroxycinnamoyltransferase EC 2.3.1.131: glucarate O-hydroxycinnamoyltransferase EC 2.3.1.132: glucarolactone O-hydroxycinnamoyltransferase EC 2.3.1.133: shikimate O-hydroxycinnamoyltransferase EC 2.3.1.134: galactolipid O-acyltransferase EC 2.3.1.135: phosphatidylcholine—retinol O-acyltransferase EC 2.3.1.136: polysialic-acid O-acetyltransferase EC 2.3.1.137: carnitine O-octanoyltransferase EC 2.3.1.138: putrescine N-hydroxycinnamoyltransferase EC 2.3.1.139: ecdysone O-acyltransferase EC 2.3.1.140: rosmarinate synthase EC 2.3.1.141: galactosylacylglycerol O-acyltransferase EC 2.3.1.142: glycoprotein O-fatty-acyltransferase EC 2.3.1.143: β-glucogallin—tetrakisgalloylglucose O-galloyltransferase EC 2.3.1.144: anthranilate N-benzoyltransferase EC 2.3.1.145: piperidine N-piperoyltransferase EC 2.3.1.146: pinosylvin synthase EC 2.3.1.147: glycerophospholipid arachidonoyl-transferase (CoA-independent) EC 2.3.1.148: glycerophospholipid acyltransferase (CoA-dependent) EC 2.3.1.149: platelet-activating factor acetyltransferase EC 2.3.1.150: salutaridinol 7-O-acetyltransferase EC 2.3.1.151: 2,3′,4,6-tetrahydroxybenzophenone synthase EC 2.3.1.152: alcohol O-cinnamoyltransferase EC 2.3.1.153: anthocyanin 5-(6′′′-hydroxycinnamoyltransferase) EC 2.3.1.154: Now EC 2.3.1.176 EC 2.3.1.155: acetyl-CoA C-myristoyltransferase EC 2.3.1.156: phloroisovalerophenone synthase EC 2.3.1.157: glucosamine-1-phosphate N-acetyltransferase EC 2.3.1.158: phospholipid:diacylglycerol acyltransferase EC 2.3.1.159: acridone synthase EC 2.3.1.160: vinorine synthase EC 2.3.1.161: lovastatin nonaketide synthase EC 2.3.1.162: taxadien-5α-ol O-acetyltransferase EC 2.3.1.163: 10-hydroxytaxane O-acetyltransferase EC 2.3.1.164: isopenicillin-N N-acyltransferase EC 2.3.1.165: 6-methylsalicylic acid synthase EC 2.3.1.166: 2α-hydroxytaxane 2-O-benzoyltransferase EC 2.3.1.167: 10-deacetylbaccatin III 10-O-acetyltransferase EC 2.3.1.168: dihydrolipoyllysine-residue (2-methylpropanoyl)transferase EC 2.3.1.169: CO-methylating acetyl-CoA synthase EC 2.3.1.170: 6′-deoxychalcone synthase EC 2.3.1.171: anthocyanin 6′′-O-malonyltransferase EC 2.3.1.172: anthocyanin 5-O-glucoside 6′′′-O-malonyltransferase EC 2.3.1.173: flavonol-3-O-triglucoside O-coumaroyltransferase EC 2.3.1.174: 3-oxoadipyl-CoA thiolase EC 2.3.1.175: deacetylcephalosporin-C acetyltransferase EC 2.3.1.176: propanoyl-CoA C-acyltransferase EC 2.3.1.177: 3,5-dihydroxybiphenyl synthase EC 2.3.1.178: diaminobutyrate acetyltransferase EC 2.3.1.179: β-ketoacyl-[acyl-carrier-protein] synthase II EC 2.3.1.180: β-ketoacyl-[acyl-carrier-protein] synthase III EC 2.3.1.181: lipoyl(octanoyl) transferase EC 2.3.1.182: Now covered by EC 2.3.3.21 EC 2.3.1.183: phosphinothricin acetyltransferase EC 2.3.1.184: acyl-homoserine-lactone synthase EC 2.3.1.185: tropine acyltransferase EC 2.3.1.186: pseudotropine acyltransferase EC 2.3.1.187: acetyl-S-ACP:malonate ACP transferase EC 2.3.1.188: ω-hydroxypalmitate O-feruloyl transferase EC 2.3.1.189: mycothiol synthase EC 2.3.1.190: acetoin dehydrogenase EC 2.3.1.191: UDP-3-O-(3-hydroxyacyl)glucosamine N-acyltransferase EC 2.3.1.192: glycine N-phenylacetyltransferase EC 2.3.1.193: tRNAMetcytidine acetyltransferase EC 2.3.1.194: acetoacetyl-CoA synthase EC 2.3.1.195: (Z)-3-hexen-1-ol acetyltransferase EC 2.3.1.196: benzyl alcohol O-benzoyltransferase EC 2.3.1.197: dTDP-3-amino-3,6-dideoxy-α-D-galactopyranose 3-N-acetyltransferase EC 2.3.1.198: glycerol-3-phosphate 2-O-acyltransferase EC 2.3.1.199: very-long-chain 3-oxoacyl-CoA synthase EC 2.3.1.200: lipoyl amidotransferase EC 2.3.1.201: UDP-2-acetamido-3-amino-2,3-dideoxy-glucuronate N-acetyltransferase EC 2.3.1.202: UDP-4-amino-4,6-dideoxy-N-acetyl-β-L-altrosamine N-acetyltransferase EC 2.3.1.203: UDP-N-acetylbacillosamine N-acetyltransferase EC 2.3.1.204: octanoyl-[GcvH]:protein N-octanoyltransferase EC 2.3.1.205: fumigaclavine B O-acetyltransferase EC 2.3.1.206: 3,5,7-trioxododecanoyl-CoA synthase EC 2.3.1.207: β-ketodecanoyl-[acyl-carrier-protein] synthase EC 2.3.1.208: 4-hydroxycoumarin synthase EC 2.3.1.209: dTDP-4-amino-4,6-dideoxy-D-glucose acyltransferase EC 2.3.1.210: dTDP-4-amino-4,6-dideoxy-D-galactose acyltransferase EC 2.3.1.211: bisdemethoxycurcumin synthase EC 2.3.1.212: benzalacetone synthase EC 2.3.1.213: cyanidin 3-O-(6-O-glucosyl-2-O-xylosylgalactoside) 6′′′-O-hydroxycinnamoyltransferase EC 2.3.1.214: pelargonidin 3-O-(6-caffeoylglucoside) 5-O-(6-O-malonylglucoside) 4′′′-malonyltransferase EC 2.3.1.215: anthocyanin 3-O-glucoside 6-O-hydroxycinnamoyltransferase EC 2.3.1.216: 5,7-dihydroxy-2-methylchromone synthase EC 2.3.1.217: curcumin synthase EC 2.3.1.218: phenylpropanoylacetyl-CoA synthase EC 2.3.1.219: demethoxycurcumin synthase EC 2.3.1.220: 2,4,6-trihydroxybenzophenone synthase EC 2.3.1.221: noranthrone synthase EC 2.3.1.222: phosphate propanoyltransferase EC 2.3.1.223: 3-oxo-5,6-didehydrosuberyl-CoA thiolase EC 2.3.1.224: acetyl-CoA-benzylalcohol acetyltransferase EC 2.3.1.225: protein S-acyltransferase EC 2.3.1.226: carboxymethylproline synthase EC 2.3.1.227: GDP-perosamine N-acetyltransferase EC 2.3.1.228: isovaleryl-homoserine lactone synthase EC 2.3.1.229: 4-coumaroyl-homoserine lactone synthase EC 2.3.1.230: 2-heptyl-4(1H)-quinolone synthase EC 2.3.1.231: tRNAPhe {7-[3-amino-3-(methoxycarbonyl)propyl]wyosine37 -N}-methoxycarbonyltransferase EC 2.3.1.232: methanol O-anthraniloyltransferase EC 2.3.1.233: 1,3,6,8-tetrahydroxynaphthalene synthase EC 2.3.1.234: N6-L-threonylcarbamoyladenine synthase EC 2.3.1.235: tetracenomycin F2 synthase EC 2.3.1.236: 5-methylnaphthoic acid synthase EC 2.3.1.237: neocarzinostatin naphthoate synthase EC 2.3.1.238: monacolin J acid methylbutanoate transferase EC 2.3.1.239: 10-deoxymethynolide synthase EC 2.3.1.240: narbonolide synthase EC 2.3.1.241: Kdo2-lipid IVA lauroyltransferase EC 2.3.1.242: Kdo2-lipid IVA palmitoleoyltransferase EC 2.3.1.243: lauroyl-Kdo2-lipid IVA myristoyltransferase EC 2.3.1.244: 2-methylbutanoate polyketide synthase EC 2.3.1.245: 3-hydroxy-5-phosphooxypentane-2,4-dione thiolase EC 2.3.1.246: 3,5-dihydroxyphenylacetyl-CoA synthase EC 2.3.1.247: 3-keto-5-aminohexanoate cleavage enzyme EC 2.3.1.248: spermidine disinapoyl transferase EC 2.3.1.249: spermidine dicoumaroyl transferase EC 2.3.1.250: [Wnt protein] O-palmitoleoyl transferase EC 2.3.1.251: lipid IVA palmitoyltransferase EC 2.3.1.252: mycolipanoate synthase EC 2.3.1.253: phloroglucinol synthase EC 2.3.1.254: N-terminal methionine Nα-acetyltransferase NatB EC 2.3.1.255: N-terminal amino-acid Nα-acetyltransferase NatA EC 2.3.1.256: N-terminal methionine Nα-acetyltransferase NatC EC 2.3.1.257: N-terminal L-serine Nα-acetyltransferase NatD EC 2.3.1.258: N-terminal methionine Nα-acetyltransferase NatE EC 2.3.1.259: N-terminal methionine Nα-acetyltransferase NatF EC 2.3.1.260: tetracycline polyketide synthase EC 2.3.1.261: (4-hydroxyphenyl)alkanoate synthase EC 2.3.1.262: anthraniloyl-CoA anthraniloyltransferase EC 2.3.1.263: 2-amino-4-oxopentanoate thiolase EC 2.3.1.264: β-lysine N6-acetyltransferase EC 2.3.1.265: phosphatidylinositol dimannoside acyltransferase EC 2.3.1.266: [ribosomal protein S18]-alanine N-acetyltransferase EC 2.3.1.267: [ribosomal protein S5]-alanine N-acetyltransferase EC 2.3.1.268: ethanol O-acetyltransferase EC 2.3.1.269: apolipoprotein N-acyltransferase EC 2.3.1.270: lyso-ornithine lipid O-acyltransferase EC 2.3.1.271: L-glutamate-5-semialdehyde N-acetyltransferase EC 2.3.1.272: 2-acetylphloroglucinol acetyltransferase EC 2.3.1.273: diglucosylglycerate octanoyltransferase EC 2.3.1.274: phosphate acyltransferase EC 2.3.1.275: acyl phosphate:glycerol-3-phosphate acyltransferase EC 2.3.1.276: galactosamine-1-phosphate N-acetyltransferase EC 2.3.1.277: 2-oxo-3-(phosphooxy)propyl 3-oxoalkanoate synthase EC 2.3.1.278: mycolipenoyl-CoA—2-(long-chain-fatty acyl)-trehalose mycolipenoyltransferase EC 2.3.1.279: long-chain-acyl-CoA—trehalose acyltransferase EC 2.3.1.280: (aminoalkyl)phosphonate N-acetyltransferase EC 2.3.1.281: 5-hydroxydodecatetraenal polyketide synthase EC 2.3.1.282: phenolphthiocerol/phthiocerol/phthiodiolone dimycocerosyl transferase EC 2.3.1.283: 2′-acyl-2-O-sulfo-trehalose (hydroxy)phthioceranyltransferase EC 2.3.1.284: 3′-(hydroxy)phthioceranyl-2′-palmitoyl(stearoyl)-2-O-sulfo-trehalose (hydroxy)phthioceranyltransferase EC 2.3.1.285: (13S,14R)-1,13-dihydroxy-N-methylcanadine 13-O-acetyltransferase EC 2.3.1.286: protein acetyllysine N-acetyltransferase EC 2.3.1.287: phthioceranic/hydroxyphthioceranic acid synthase EC 2.3.1.288: 2-O-sulfo trehalose long-chain-acyltransferase EC 2.3.1.289: aureothin polyketide synthase system EC 2.3.1.290: spectinabilin polyketide synthase system EC 2.3.1.291: sphingoid base N-palmitoyltransferase EC 2.3.1.292: (phenol)carboxyphthiodiolenone synthase EC 2.3.1.293: meromycolic acid 3-oxoacyl-(acyl carrier protein) synthase I EC 2.3.1.294: meromycolic acid 3-oxoacyl-(acyl carrier protein) synthase II EC 2.3.1.295: mycoketide-CoA synthase EC 2.3.1.296: ω-hydroxyceramide transacylase EC 2.3.1.297: very-long-chain ceramide synthase EC 2.3.1.298: ultra-long-chain ceramide synthase EC 2.3.1.299: sphingoid base N-stearoyltransferase EC 2.3.1.300: branched-chain β-ketoacyl-[acyl-carrier-protein] synthase EC 2.3.1.301: mycobacterial β-ketoacyl-[acyl carrier protein] synthase III EC 2.3.1.302: hydroxycinnamoyl-CoA:5-hydroxyanthranilate N-hydroxycinnamoyltransferase EC 2.3.1.303: α-L-Rha-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-α-D-Gal-PP-Und 2IV-O-acetyltransferase EC 2.3.1.304: poly[(S)-3-hydroxyalkanoate] polymerase
== Reception == The film received a mixed critical reaction. Rotten Tomatoes gives it a score of 48% based on 21 reviews, with an average rating of 4.89/10. Jeanette Catsoulis of The New York Times praised Chastain's performance, noting that she "digs deep. Surrendering to her character’s smoky voice-over and disastrous judgment, the actress finds pockets of soul in a role that’s part Jessica Rabbit, part Marilyn Monroe." Rex Reed of The New York Observer rated the film three out of four stars. Reed praised the casting; "This movie boasts a terrific cast, and Ms. Chastain not only holds her own corner of every scene, she's the only thing you want to watch."
Sources: en.wikipedia.org
Tyrosine hydroxylase activity is increased in the short term by phosphorylation. The regulatory domain of tyrosine hydroxylase contains multiple serine (Ser) residues, including Ser8, Ser19, Ser31 and Ser40, that are phosphorylated by a variety of protein kinases. Ser40 is phosphorylated by the cAMP-dependent protein kinase. Ser19 (and Ser40 to a lesser extent) is phosphorylated by the calcium-calmodulin-dependent protein kinase. MAPKAPK2 (mitogen-activated-protein kinase-activating protein kinase) has a preference for Ser40, but also phosphorylates Ser19 about half the rate of Ser40. Ser31 is phosphorylated by ERK1 and ERK2 (extracellular regulated kinases 1&2), and increases the enzyme activity to a lesser extent than for Ser40 phosphorylation. The phosphorylation at Ser19 and Ser8 has no direct effect on tyrosine hydroxylase activity. But phosphorylation at Ser19 increases the rate of phosphorylation at Ser40, leading to an increase in enzyme activity. Phosphorylation at Ser19 causes a two-fold increase of activity, through a mechanism that requires the 14-3-3 proteins. Phosphorylation at Ser31 causes a slight increase of activity, and here the mechanism is unknown. Tyrosine hydroxylase is somewhat stabilized to heat inactivation when the regulatory serines are phosphorylated. Tyrosine hydroxylase is mainly present in the cytosol, although it also is found in some extent in the plasma membrane. The membrane association may be related to catecholamine packing in vesicles and export through the synaptic membrane.
=== Half-Life: Uplink === A short film, Half-Life: Uplink, (which is unrelated to the demo of the same name) was developed by Cruise Control, a British marketing agency, and released on March 15, 1999. However, Sierra withdrew it from circulation after Sierra and Valve had failed to resolve licensing issues with Cruise Control over the film. The critical reception of the film was very poor. The film's plot was that of a journalist attempting to infiltrate the Black Mesa Research Facility and discover what was happening there.
In boosted fission weapons a mix of 2H and 3H is heated until there is thermonuclear fusion to produce helium and free neutrons. These fast neutrons then cause further fission, creating "boosting". In 1951, in Operation Greenhouse, a prototype named George, validated the proof of concept for such a weapon. However, the first true boosted fission bomb, Greenhouse Item, was successfully tested in 1952, giving a 45.5-kiloton yield, nearly double that of an unboosted bomb. The United States stopped producing tritium in nuclear reactors in 1988, but nuclear tests in the 1950s added large spikes of radionuclides to the air, especially carbon-14 and 3H. This complicated measurements for geologists using carbon dating. However, some oceanographers benefited from the 3H increase, using the signal in the water to trace physical mixing of water masses.
DNA sequencing, one of the most fundamental technologies developed to study genetics, allows researchers to determine the sequence of nucleotides in DNA fragments. The technique of chain-termination sequencing, developed in 1977 by a team led by Frederick Sanger, is still routinely used to sequence DNA fragments. Using this technology, researchers have been able to study the molecular sequences associated with many human diseases. As sequencing has become less expensive, researchers have sequenced the genomes of many organisms using a process called genome assembly, which uses computational tools to stitch together sequences from many different fragments. These technologies were used to sequence the human genome in the Human Genome Project completed in 2003. New high-throughput sequencing technologies are dramatically lowering the cost of DNA sequencing, with many researchers hoping to bring the cost of resequencing a human genome down to a thousand dollars. Next-generation sequencing (or high-throughput sequencing) came about due to the ever-increasing demand for low-cost sequencing. These sequencing technologies allow the production of potentially millions of sequences concurrently. The large amount of sequence data available has created the subfield of genomics, research that uses computational tools to search for and analyze patterns in the full genomes of organisms. Genomics can also be considered a subfield of bioinformatics, which uses computational approaches to analyze large sets of biological data.
In the back of the chamber, there is packing around the piston or a doughnut-shaped seal with a toroid-shaped sphincter-like spring inside compressing the seal around the piston. This holds the fluid pressure when the piston slides in and out and makes the pump leak-tight. The packing or seals can wear out after prolonged use and can be replaced. The metering rate can be adjusted by varying the strokelength by which the piston moves back and forth or varying the speed of the piston motion. A single-piston pump delivers liquid to the outlet only during the discharge stroke. If the piston's suction and discharge strokes occur at the same speed and liquid is metered out half the time the pump is working, then the overall metering rate averaged over time equals half the average flow rate during the discharge stroke. Some single-piston pumps may have a constant slow piston motion for discharge and a quick retract motion for refilling the pump head. In such cases, the overall metering rate is practically equal to the pumping rate during the discharge stroke.
Sources: en.wikipedia.org
== Etymology == The genus name Anethum is the Latin form of Greek ἄνῑσον / ἄνησον / ἄνηθον / ἄνητον, which meant both "dill" and "anise". The form 'anīsum' came to be used for anise, and 'anēthum' for dill. The Latin word is the origin of dill's names in the Western Romance languages ('anet', 'aneldo' etc.), and also of the obsolete English 'anet'. The word dill and its close relatives are found in most of the Germanic languages; its ultimate origin is unknown.
Reuse of needles and syringes has caused spread of diseases, especially HIV and hepatitis, among intravenous drug users. Syringes are also commonly reused by diabetics, as they can go through several in a day with multiple daily insulin injections, which becomes an affordability issue for many. Even though the syringe and needle are only used by a single person, this practice is still unsafe as it can introduce bacteria from the skin into the bloodstream and cause serious and sometimes lethal infections. In medical settings, single-use needles and syringes effectively reduce the risk of cross-contamination. Medical syringes are sometimes used without a needle for orally administering liquid medicines to young children or animals, or milk to small young animals, because the dose can be measured accurately and it is easier to squirt the medicine into the subject's mouth instead of coaxing the subject to drink out of a measuring spoon.
=== In cytoplasmatic actins === ACTB is a highly complex locus. A number of pseudogenes exist that are distributed throughout the genome, and its sequence contains six exons that can give rise to up to 21 different transcriptions by alternative splicing, which are known as the β-actins. Consistent with this complexity, its products are also found in a number of locations and they form part of a wide variety of processes (cytoskeleton, NuA4 histone-acyltransferase complex, cell nucleus) and in addition they are associated with the mechanisms of a great number of pathological processes (carcinomas, juvenile dystonia, infection mechanisms, nervous system malformations and tumour invasion, among others). A new form of actin has been discovered, kappa actin, which appears to substitute for β-actin in processes relating to tumours.
== Background == The measurement of scattered light from an illuminated sample forms the basis of the so-called classical light scattering measurement. Historically, such measurements were made using a single detector rotated in an arc about the illuminated sample. The first commercial instrument (formally called a "scattered photometer") was the Brice-Phoenix light scattering photometer introduced in the mid-1950s and followed by the Sofica photometer introduced in the late 1960s. Measurements were generally expressed as scattered intensities or scattered irradiance. Since the collection of data was made as the detector was placed at different locations on the arc, each position corresponding to a different scattering angle, the concept of placing a separate detector at each angular location of interest was well understood, though not implemented commercially until the late 1970s. Multiple detectors having different quantum efficiency have different response and hence needs to be normalized in this scheme. An interesting system based upon the use of high speed film was developed by Brunsting and Mullaney in 1974. It permitted the entire range of scattered intensities to be recorded on the film with a subsequent densitometer scan providing the relative scattered intensities. The then-conventional use of a single detector rotated about an illuminated sample with intensities collected at specific angles was called differential light scattering after the quantum mechanical term differential cross section, σ(θ) expressed in milli-barns/steradian.
=== Amino acid substitution === Incorporating amino acids that deviate from the genetic code predictions is usually detected as amino acid substitutions in proteins and peptides. Such alternate RNA decoding results in stable and abundant proteins in both mouse and human tissues. The abundance of such substitutions is determined by multiple mechanisms, including codon frequency, codon–anticodon mismatches, RNA modifications, and protein stability. In some cells certain amino acids can be depleted and thus affect translation efficiency. For instance, activated T cells secrete interferon-γ which triggers intracellular tryptophan shortage by upregulating the indoleamine 2,3-dioxygenase 1 (IDO1) enzyme. Despite tryptophan depletion, in-frame protein synthesis continues across tryptophan codons. This is achieved by incorporation of phenylalanine instead of tryptophan. The resulting peptides are called W>F "substitutiant". Such W>F substitutiant are abundant in certain cancer types and have been associated with increased IDO1 expression. Functionally, W>F substitutiants can impair protein activity.
Sources: en.wikipedia.org
Usually not, though usage overlaps. The label most often refers to a short acetylated fragment of the parent protein, while thymosin beta-4 itself is the full 43-residue molecule. Because suppliers vary, a sequence statement is needed to settle the question for any particular lot.
The name is a commercial label rather than a systematic chemical designation, so different vendors and papers attach it to different sequences. Some treat it as a fragment and others as the whole protein. Comparing two reports therefore requires checking what each one actually analyzed.
Typically it reflects the relative area of the main peak in a reversed-phase chromatogram at a given wavelength. It does not confirm the amino acid sequence, the counter-ion, or the amount of peptide by mass. Identity is normally established by a separate mass measurement.
TB-500 is a trade-style label for a synthetic peptide connected to thymosin beta-4. It is sold mainly through research-chemical channels and is not a single chemically defined product across suppliers.