Calf thymus peptide

Protein A24 is histone H2A into which the peptide ubiquitin is covalently attached via its carboxy-terminal end to the e-amino of lysine 119 of H2A (Goldknopf et al., 1977). A24 is a constituent of nucleo-somes and is present to the extent of 10% of calf thymus H2A (Busch... 

Experimentally, anti-dsDNA antibodies have been successfully induced by a complex of native calf thymus DNA and a highly immunogenic DNA-binding peptide Fusl (D7). 

Thymopoietin, a calf thymus polypeptide with 49 amino acids, causes selective T-cell differentiation and is therefore responsible for the cell-bound immune reaction. Consideration of smaller peptides having the same properties with respect to the immune system led to the synthetic thymopentin Arg-Lys-Asp-Val-Tyr 131 132) and derivatives such as Lys-Lys-Tyr-Phe-Arg 133). 

Thymomodulin. Leucotrofina. Cell-tree thymic hormone preparation extracted from calf thymus by acid hydrolysis Composed of a mixture of biologically active acidic peptides of mol wt < 10,000. Modulates the maturation of T-cells, Prepn of crude extract from calf thymus B, Bruneiti, E. Pini, US. pat. 3,657,417 (1972 to Eltem). Electrophoretic characterization C. Secchi er at.. Rip. Ear. Set. Med. Farmacol. 4, 499 (]982), C.A. 01, 21878m (]9S4). Biological activity and comparison with other thymic hormones J. J. Twomey, N, M, Kouttab. Cell. Immunol 12, 186 (1982). Purification and pharmacodynamics eidem. 

The data described above suggest that the ADP-ribosylated arginine may be sequenced near serine residue 38 which is phosphorylated by cAMP-dependent protein kinase (Fig. 3). In the experiment of protein kinase-catalyzed phosphorylation of synthetic peptide, Zetterqvist et al. [9] and Kemp et al. [10] proposed that two arginine residues are necessary at the N-terminal side of phosphate-accepting serine residue. Therefore, we speculated that the ADP-ribosylation may influence the cAMP-dependent protein kinase activity. Actually, we found that when whole histones from calf thymus were... 

In a remarkable cooperative program between Emil Smith s and James Bonner s laboratories [65, 66], the complete amino acid sequence of the 102 residues of calf thymus histone 4 was established from the chymo-tryptic and tryptic peptides of the purified protein. This study reveals two important characteristics of the histone sequence the presence of an unusual amino acid—acetyllysine—in position 16 and the clustering... 

Further, Weissman and Graff (621) noted that calf thymus histone also inhibits the respiration of B. anthracis, and that this inhibition is reversed by deoxyribonucleic acid. The concentration of lysine per unit of anthracidal activity is the same for the basic polypeptide and for the histone of thymus. Weissman and Graff (621) hypothesized that the basic polypeptide is a constituent of histone and is liberated from the histone by the acid and heat treatment used for the extraction of the peptide. 

Fig. 7 Identification of novel posttranslational modifications of histones H2A and H2B isolated from calf thymus nuclei by FT-ICR MS analysis of proteolytic peptides generated by the digestion of histone H2A with pepsin (a) or trypsin (b), and of histone H2B with trypsin (c) and V8DE (d). Reproduced from [375]...

The E. colt poly(A) polymerase is a monomeric enzyme of 55 kDa. A highly purified preparation of the enzyme from E. colt K12 apparently exhibits doublet bands having a 3-kDa difference in SDS—PAGE. The N termini of the doublet components are identical and start with Lys. Presumably, poly(A) polymerase is synthesized as a precursor consisting of 472 amino acid residues (calc. 54 kDa), and the N-terminal 17 amino acid peptide is cleaved at the Arg-Lys junction (37). The . colt poly(A) polymerase shows no obvious sequence similarities with the corresponding enzymes from calf thymus (38), vaccinia virus (39), and yeast (40). 

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