title: [Some properties of peptidase from rat heart, breaking down luliberin].
abstract: The properties of rat heart peptidase hydrolyzing luliberin were studied. This peptidase was shown to be a sulfhydryl metalloenzyme with m.w. of about 100000. The maximal enzyme activity was observed at neutral values of pH Ca2+ (5 X 10(-6) M) increased the enzyme activity by 50%, thus being indicative of an anomalous dependence of the enzyme activity of substrate concentration. At luliberin concentrations of 10(-7)-10(-6) M the enzyme activation by Ca2+ was considerably reduced and returned to the initial level when the peptide concentration was increased up to 10(-5) M. It was assumed that the peptidase under study is a regulatory enzyme whose activity depends on concentrations of Ca2+ and of the reaction substrate, luliberin.
mesh_terms: D000818:Animals; D002118:Calcium / Q000494:pharmacology; D004789:Enzyme Activation; D005260:Female; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D007986:Luteinizing Hormone / Q000378:metabolism*; D009206:Myocardium / Q000201:enzymology*; D010447:Peptide Hydrolases / Q000302:isolation & purification / Q000378:metabolism*; D051381:Rats
chemical_list: D007986:Luteinizing Hormone; D010447:Peptide Hydrolases; D002118:Calcium
vernacular_title: Nekotorye svoĭstva peptidazy iz serdtsa krysy, rasshchepliaiushcheĭ liuliberin.