Prochymosin activation by non-aspartic proteinases.
Prochymosin can be converted into chymosin by an action of external proteinases. Thus, thermolysin at pH 5.05 converts calf prochymosin into active Phe-chymosin, which is one amino acid longer than chymosin from the N-terminus with a yield of 73%. Even better results were achieved with prochymosin activation by Legionella pneumophila metalloproteinase. Apparently the stretch of prochymosin polypeptide chain adjacent to the normally observed activation point becomes available for an attack by an external proteinase at pH 5.0-6.0. These data indicate that the intermolecular activation pathway might be of physiological importance.
Stepanov
V M
VM
Institute of Genetics and Selection of Industrial Microorganism, Moscow, USSR.
Lavrenova
G I
GI
Terent'eva EYu
Khodova
O M
OM
D000595:Amino Acid Sequence; D000818:Animals; D001224:Aspartic Acid / Q000378:metabolism; D001665:Binding Sites; D001711:Biotransformation; D002417:Cattle; D012085:Chymosin / Q000032:analysis / Q000096:biosynthesis / Q000378:metabolism*; D004792:Enzyme Precursors / Q000378:metabolism*; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000032:analysis; D010447:Peptide Hydrolases / Q000378:metabolism*; D012697:Serine Endopeptidases / Q000378:metabolism; D013820:Thermolysin / Q000378:metabolism*
D004792:Enzyme Precursors; D010446:Peptide Fragments; D001224:Aspartic Acid; D010447:Peptide Hydrolases; D012697:Serine Endopeptidases; C032443:prorennin; D012085:Chymosin; D013820:Thermolysin