Some properties of peptidase from rat heart, breaking down luliberin
Tsibezov, V.V.
Biokhimiia 48(8): 1384-1389
1983
ISSN/ISBN: 0320-9725 PMID: 6354276 Document Number: 218355
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.