Characterization of a cAMP-independent Ca2 (+) -inhibited protamine kinase from Candida lipolytica
Rahmatullah, M.; Brenner, D.L.; Wooten, M.W.; Weete, J.D.
Biochemical and biophysical research communications 175(2): 500-506
1991
ISSN/ISBN: 0006-291X PMID: 1850244 Document Number: 367988
A cAMP-independent protamine kinase has been purified from extracts of the yeast Candida lipolytica by ion-exchange and affinity chromatography. Two subunits with apparent Mr's of 52,000 and 36,000 where resolved by SDS-PAGE. The purified kinase exhibited about 20% activity wit casein and histone Type VII-S as substrates relative to protamine. The enzyme was inactive against other protein substrates tested, and was essentially insensitive to AMP, cAMP, cGMP up to 0.2 mM, the polyamines spermine and spermidine up to 1 mM, N-ethylmaleimide (5 mM), 2-mercaptoethanol (20 mM), or dithiothreitol (2 mM), and several cations like Zn2+, N1+, or Co2+ at 0.1 mM each. Ca2+ at 3 mM inhibited protamine kinase activity by 50%, which was reversed by EGTA.