The primary structure of rat parathymosin.

Abstract

authors request that the following error be noted on p. 1272, in the second paragraph from the bottom of the right-hand column. The bacteriophage T4 gene identified by Belfort and colleagues (ref. 53) as containing an intron encodes thymidylate synthase, not thymidine kinase. CorrectionsProc. Nail. Acad. Sci. USA Vol. 83, pp. 1242-1245, March 1986 BiochemistryThe primary structure of rat parathymosin ABSTRACTParathymosin has been isolated from rat thymus and from rat liver. Its primary structure is reported 10 as follows:AcSer-Lys-Ser-Glu-Val -Glu-Ala-Ala-Ala-Glu -20 Leu-Ser-Ala-Lys-Asp-Leu-Lys-Glu-Lys-Lys -Asp-Lys- Glu-Glu-Lys-Ala-Gly-Arg-Lys-Glu-Arg-Lys-Lys-Glu- Val-Glu-Glu-Glu -Glu-Asn-Gly-Ala-Glu-Glu-Glu-Glu-Gluso 80Glu -Thr-Ala-Glu-(Gly3,Asx7,Glx14)-Glu-Gly-Pro -Val-Arg- 90Lys-Arg-Thr-Ala-Glu-Glu-Glu-Asp -Glu-Ala-Asp-Pro-Lys- 100Arg-Gln-Lys-Thr-Glu Asn-Gly-Ala-Ser-AlaOH. The blockmg group at the NH2 terminus was identified by mass spectrometry as acetyl. Regions homologous to amino acid sequences in prothymosin a were found to be located between residues 14-20, 23-25, 33-39, 41-43, and 83-87 of parathymosin.Parathymosin was first isolated from rat thymus (1) as a by-product of the procedure used for the isolation of prothymosin a. It was named parathymosin because of its structural similarity to prothymosin a, the putative precursor of thymosin a1 (2, 3 In the present paper, we report a simplified procedure for the isolation of both peptides from rat thymus and the nearly complete amino acid sequence ofparathymosin. A procedure for the isolation of parathymosin from rat liver, a richer source for this peptide, is also described. MATERIALS AND METHODSMaterials. Rat tissues were collected immediately after sacrifice of the animals by decapitation, frozen in liquid N2, and stored at -70'C. Other materials were from sources identified earlier (1, 3, 4).Methods. Chromatography on Sephacryl S-200 was carried out as described (1). For the HPLC, a Waters Associates system with an Altex Ultrasphere ODS C18 column was used.Protein and peptide analyses were carried out fluorometrically following alkaline hydrolysis and reaction with fluorescamine (7). Automated sequence analysis was as described (3). The quantitative radioimmunoassay for prothymosin a was as described by Haritos and Horecker (4 9.0 with K2CO3. After 4 hr at 50°C, the solution was acidified with 26 ul of concentrated HCOOH, diluted with 10 ml of buffer A (1 M HCOOH/0.2 M pyridine, pH 2.8) and pumped through a Sep-Pak C18 cartridge. After the cartridge was washed with 10 ml of buffer A, the peptides were eluted with 3 ml of 40% acetonitrile in buffer A, and the eluate was lyophilized.Digestion with Staphylococcus aureus V8 protease was in 25 ,ul of 0.1 M NH4HCO3 containing 50 ,ug of peptide, 2 mM EDTA, and 1.67 ,ug of protease. After 13 hr at 37°C, the solution was lyophilized.For the isolation of peptides in the proteinase digests and after treatment with H2NOH, the lyophilized solutions were dissolved in buffer A and separated by HPLC using the OD...

Sequencing of peptides and proteins with blocked N-terminal amino acids: N-acetylserine or N-acetylthreonine.

“…Human, bovine, and rat parathymosins were isolated from liver as described (11). Bovine and rat prothymosins a were isolated from thymus glands (11). Thymosin P4 was purified from rat thymus (12).…”

Isolation and partial characterization of prothymosin α from porcine tissues

“…Prothymosin cy from thymus, spleen, lung and kidney was purified according to Haritos et al [l], as modified in [17]. Briefly, 10 g of unthawed tissue was pulverized in liquid Nz and immediately added to 200 ml boiling water.…”

Macromolecular Translocation Inhibitor II (Zn2+-binding Protein, Parathymosin) Interacts with the Glucocorticoid Receptor and Enhances Transcription in Vivo

“…Haritos et al (10,14) initially isolated MTI-II from rat thymus as parathymosin, a homolog of the protein prothymosin ␣ (PT␣). MTI-II/ parathymosin shares 46% identity with PT␣ (14), but the two proteins show a reciprocal tissue distribution in rats (10,12).…”

“…MTI-II/ parathymosin shares 46% identity with PT␣ (14), but the two proteins show a reciprocal tissue distribution in rats (10,12). MTI-II and PT␣ were thought to be the native proteins or the putative precursor peptides of thymosin ␣1, the immunomodulatory polypeptide (or "thymic hormone") that influences lymphocyte maturation.…”