Enzymatic activity of prostate-specific antigen and its reactions with extracellular serine proteinase inhibitors.

摘要: Prostate-specific antigen (PSA) is one of the three most abundant prostatic-secreted proteins in human semen. It a serine proteinase that, its primary structure, manifests extensive similarities with that Arg-restricted glandular kallikrein-like proteinases. When isolated from semen by addition chromatography on aprotinin-Sepharose to previously described procedure, PSA displayed chymotrypsin-like activity and cleaved semenogelin semenogelin-related rapid characteristic pattern, but had no trypsin-like activity. About third purified protein was found be enzymatically inactive, due cleavage carboxy-terminal Lys145. Active formed SDS-stable complexes alpha 1-antichymotrypsin, 2-macroglobulin-analogue pregnancy zone protein. inhibitory 1-antichymotrypsin at molar ratio 1:1, reaction which inhibitor position identical reported between chymotrypsin 1-antichymotrypsin. The formation stable occurred much slower rate than similar or slightly 2-macroglobulin. added normal blood plasma vitro, active both 2-macroglobulin This complex may crucial determinant turnover intercellular fluid vivo.