title: Purification and preliminary characterization of Torresea cearensis trypsin inhibitor.
abstract: An inhibitor against serine proteinases was purified from Torresea cearensis by affinity chromatography on trypsin-Sepharose. The protein is a single polypeptide of molecular weight 13,600 after reduction and has a high content of cysteine residues. Both trypsin (Ki = 0.34 nM) and chymotrypsin (Ki = 0.15 microM) are inhibited by Torresea cearensis inhibitor. Blood clotting factor XII is also inhibited (Ki = 0.24 microM), but not plasma kallikrein, tissue kallikrein or thrombin. The stoichiometry of the inhibitor-proteinase complex with trypsin is 1:1.
authors.affiliation: Departamento de Bioquímica, Escola Paulista de Medicina, São Paulo, Brasil.
authors.forename: A S
authors.initials: AS
authors.lastname: Tanaka
authors.forename: M U
authors.initials: MU
authors.lastname: Sampaio
authors.forename: C A
authors.initials: CA
authors.lastname: Sampaio
authors.forename: M L
authors.initials: ML
authors.lastname: Oliva
mesh_terms: D007887:Fabaceae; D005174:Factor XII / Q000037:antagonists & inhibitors; D007610:Kallikreins / Q000097:blood; D010314:Partial Thromboplastin Time; D010946:Plants, Medicinal; D012639:Seeds / Q000032:analysis*; D014361:Trypsin Inhibitors / Q000302:isolation & purification* / Q000494:pharmacology
chemical_list: D014361:Trypsin Inhibitors; D005174:Factor XII; D007610:Kallikreins