Ein synthetisches pentapeptid als plastein‐monomeres. Untersuchungen über die plasteinreaktion. II

Abstract

ZUSAMMENFASSUNG:S ynthetisch erhaltenes L-Tyrosyl-L-isoleucyl-glycyl-L-glutamyl-~-phenylalanin ist unter der Wirkung von Pepsin zu einem plasteinartigen Polypeptid kondensierbar. Durch Extinktionsmessungen an der Dinitrophenylverbindung lie13 sich dessen Polymerisationsgrad zu 2 bis 3 bestimmen. SUMMARY:The pentapeptide L-tyrosyl-L-isoleucyI-glycyl-L-glutamyl-~-phenylalanine has been synthesized and proved to be a monomer in the plastein reaction with pepsin as a catalyst.The molecular weight of the plastein so formed was -2250 as determined by UV spectrophotometry of its DNP-derivative.

Proteinase‐Catalyzed Synthesis of Peptide Bonds

“…The first systematic experiments designed to study the ability of pepsin to catalyze the condensation of well-defined synthetic peptides were performed during the 1960s by Wieland, Determann, and their associates (265)(266)(267)(268)(269) in connection with the problem of plastein formation. Shortly before, Virtanen et al (270,27 1) had concluded that this process involves the condensation of oligopeptides with (on the average) six amino acid residues.…”

“…Shortly before, Virtanen et al (270,27 1) had concluded that this process involves the condensation of oligopeptides with (on the average) six amino acid residues. Determann and Wieland (266) found that synthetic H-Tyr-IleGly-Glu-Phe-OH is converted at pH 5 to an insoluble oligomer with an average polymerization value of 2.5, without detectable transpeptidation. In their subsequent work, higher values (2.7-6.5) were found with other pentapeptides of related structure, and they showed that the nature and configuration of the amino-and carboxyl-terminal amino acid residues are decisive (268).…”