title: [Purification and partial characterization of protease B from germinating vetch seeds].
abstract: The sulfhydryl protease B was isolated from the cotyledons of 8-day old vetch seedlings and purified 1580-fold with a 38% recovery. The preparation obtained proved to be homogeneous by DEAE-cellulose chromatography and polyacrylamide gel electrophoresis. The molecular weight of the enzyme as shown by Na-DS gel electrophoresis is 38 000. Protease B hydrolyzes the peptide bonds involving the carboxyl groups of asparagine in insulin chains A and B. Since protease B fails to attack the native reserve proteins the high molecular weight products of the initial hydrolysis of reserve proteins by the earlier discovered protease A seem to be the most probable substrates of protease B. A considerable part of these substrates is split by protease B to form large peptides. The role of protease B in reserve proteins degradation is discussed.
mesh_terms: D003546:Cysteine Endopeptidases; D010450:Endopeptidases / Q000302:isolation & purification* / Q000378:metabolism; D007700:Kinetics; D008970:Molecular Weight; D010944:Plants / Q000201:enzymology*; D013379:Substrate Specificity
chemical_list: D010450:Endopeptidases; D003546:Cysteine Endopeptidases; C034885:vetch protease B
vernacular_title: Ochistka i chastichnaia kharakteristika proteazy B iz prorastaiushchikh semian viki.