title: [An inhibitor of enteropeptidases and trypsin from the bovine duodenum].
abstract: Enteropeptidase inhibitor (DI) was isolated from bovine duodenum during purification of this enzyme. DI was purified by affinity chromatography on immobilised trypsin. DI preparations contain two main components: DI-9 (9 kD) and DI-20 (20 kD). The N-terminal amino acid sequence 1-19 of DI-9 is highly homologous to the Kunitz inhibitor (BPI). Molecular weights of DI-9 and BPI are the same (gel electrophoresis data). Fragment 1-19 of DI-9 differs from the corresponding region of BPI only at the position 17: DI-9 contains Ala-17 instead of Arg in BPI. The homology of N-terminal amino acid sequence 1-25 of DI-20 with the corresponding regions of some phospholipases A2 suggests that this protein is a new intestinal phospholipase A2. Inhibitor DI-9 and phospholipase DI-20 are probably isolated in a common lipoprotein complex. The only earlier known in vitro inhibitor of enteropeptidase, BPI, was localised in vivo in different tissues with this enzyme. In our opinion the Kunitz-type inhibitor DI-9 is, a physiological inhibitor of enteropeptidase.
authors.affiliation: Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia.
authors.forename: A G
authors.initials: AG
authors.lastname: Mikhaĭlova
authors.forename: N G
authors.initials: NG
authors.lastname: Evtiukova
authors.forename: L A
authors.initials: LA
authors.lastname: Chupova
authors.forename: L D
authors.initials: LD
authors.lastname: Rumsh
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D002846:Chromatography, Affinity; D004386:Duodenum / Q000201:enzymology / Q000378:metabolism*; D004765:Enteropeptidase / Q000037:antagonists & inhibitors*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D017386:Sequence Homology, Amino Acid; D015842:Serine Proteinase Inhibitors / Q000737:chemistry / Q000302:isolation & purification*; D014361:Trypsin Inhibitors / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D015842:Serine Proteinase Inhibitors; D014361:Trypsin Inhibitors; D004765:Enteropeptidase
vernacular_title: Ingibitor énteropeptidazy i tripsina iz dvenadtsatiperstnoĭ kishki byka.