Mechanism of plastein formation
1959; Elsevier BV; Volume: 33; Issue: 1 Linguagem: Inglês
10.1016/0006-3002(59)90519-0
ISSN1878-2434
AutoresJack Horowitz, Felix Haurowitz,
Tópico(s)Digestive system and related health
ResumoThe formation by chymotypsin of plastein from concentration peptic hydrolyzates of egg albumin has been investigated in detail. Some properties of plastein are described. Free [14C]amino acids are not incorporated into plastein to an appreciable degree. However, 14C-labeled phenylalanine, tyrosine, threonine, aspartic acid, glutamic acid, leucine and isoleucine, and histidine are incorporated into plastein when their ethyl esters and chymotrypsin are added to the concentration digest. No incorporation of [14C]glycine, alanine, serine, cystine, proline and lysine was observed. Attempts by various methods to remove the incorporated radioactivity all failed; it is presumed that the labeled amino acids are bound in peptide linkage. Since the α-amino nitrogen remains unchanged during plastein formation, it is concluded that transpeptidation reactions are primarily responsible for plastein synthesis by chymotrypsin.
Referência(s)