THE PRIMARY STRUCTURE OF CARBOXYPEPTIDASE-S3 FROM PENICILLIUM-JANTHINELLUM IBT-3991

The complete amino acid sequence of penicillopeptidase S3, a serine ca rboxypeptidase isolated from Penicillium janthinellum IBT 3991, has be en determined, The enzyme consists of 481 amino acids arranged in a si ngle polypeptide chain. Six glycosylation sites were established in po sitions 41, 218, 256, 326, 384 and 392, The molecule contains six cyst einyl residues among which disulfide bridges was established between C ys-71-Cys-333 and Cys-233-Cys-289, Carboxypeptidase S3 is homologous t o carboxypeptidase PEPF (or carboxypeptidase I) from Aspergillus niger (67% identical positions), It is proposed that these enzymes form a s eparate sub-family among the serine carboxypeptidases.