Activation of recombinant proenteropeptidase by duodenase.
Duodenase, a serine proteinase from bovine Brunner's (duodenal) glands that was predicted to be a natural activator of enteropeptidase zymogen, cleaves and activates recombinant single-chain bovine proenteropeptidase (kcat/Km = 2700 M(-1) s(-1)). The measured rate of proenteropeptidase cleavage by duodenase was about 70-fold lower compared with the rate of trypsin-mediated cleavage of the zymogen. The role of duodenase is supposed to be the primary activator of proenteropeptidase maintaining a certain level of active enteropeptidase in the duodenum. A new scheme of proteolytic activation cascade of digestive proteases is discussed.
Zamolodchikova
T S
TS
Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russia. tatyana@enzyme.siobc.ras.ru
Sokolova
E A
EA
Lu
D
D
Sadler
J E
JE
D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D004591:Electrophoresis, Polyacrylamide Gel; D004765:Enteropeptidase / Q000737:chemistry / Q000378:metabolism*; D004789:Enzyme Activation; D004792:Enzyme Precursors / Q000737:chemistry / Q000378:metabolism*; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000378:metabolism; D012697:Serine Endopeptidases / Q000378:metabolism*
D004792:Enzyme Precursors; D011994:Recombinant Proteins; D012697:Serine Endopeptidases; C078261:duodenase; D004765:Enteropeptidase