In vitro synthesis of thymosin beta 4 encoded by rat spleen mRNA.
Thymosin beta 4, containing 43 amino acids and acetylated at the NH2 terminus, is synthesized in vitro in a rabbit reticulocyte lysate or in a yeast protein-synthesis system in the presence of mRNA from rat spleen. The product formed was identified as beta 4 by immunoprecipitation by a specific anti-beta 4 antiserum, comigration with authentic beta 4 in NaDodSO4/polyacrylamide gel electrophoresis and in HPLC, and identity of peptide fragments. The immunoprecipitable product generated in the wheat germ protein-synthesizing system emerged slightly ahead of beta 4 in HPLC and appeared to lack the NH2-terminal acetyl group. There was no evidence for formation of a larger polypeptide precursor of beta 4 in any of the three systems used. In sucrose density gradient centrifugation, the mRNA coding for beta 4 was recovered in the 7-8S mRNA fraction.
D000818:Animals; D002474:Cell-Free System; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000235:genetics / Q000302:isolation & purification; D051381:Rats; D013154:Spleen / Q000502:physiology; D013947:Thymosin / Q000096:biosynthesis / Q000235:genetics* / Q000276:immunology; D013951:Thymus Hormones / Q000235:genetics*
D012333:RNA, Messenger; D013951:Thymus Hormones; D013947:Thymosin