Characterization of and Drug Influence on a Calmodulinsensitive Phosphodiesterase Purified from Bovine Brain

Publisher Website
Google Scholar
Abstract
The purification procedure involved ammonium sulfate fractionation, 2 chromatographic steps on DEAE-cellulose, gel-filtration on Sephadex G-200, and finally 1 DEAE-cellulose run, and gave a 2300-fold purification. The purified phosphodiesterase had a Vmax for cAMP of 126 .mu.mol/mg protein .times. min and was activated 8-fold by addition of calmodulin and Ca. According to SDS[sodium dodecyl sulfate]-electrophoresis, the purified enzyme contained 1 major peptide of 59,000 daltons, but the preparation was not homogeneous. The enzyme was characterized kinetically and with regard to the effect of cations, pH, temperature and nucleotides. The influence in vitro on enzyme activity of several classes of drugs, e.g., antidepressants, neuroleptics, antiallergics, platelet inhibitors, and some reference phosphodiesterase inhibitors was also investigated.