Resolution of adenylate cyclase sensitive and insensitive to Ca2+ and calcium-dependent regulatory protein (CDR) by CDR-sepharose affinity chromatography.

Abstract

Partially purified adenylate cyclase [ATP pyrophosphate-lyase (cyclizing), EC 4.6.1.1] from bovine brain cortex was fractionated into 2 separate forms by Ca-dependent regulatory protein (CDR) Sepharose affinity chromatography. The major form of the enzyme, comprising .apprxeq. 80% of the applied activity, did not bind to the affinity column in the presence of Ca2+ and was insensitive to the CDR. Approximately 20% of adenylate cyclase activity was absorbed to CDR-Sepharose in the presence of Ca2+. This activity was stimulated by Ca2+ and CDR. Brain cortex contains Ca2+ .cntdot. CDR-sensitive and -insensitive forms of adenylate cyclase. CDR-Sepharose may be a useful tool for purification of adenylate cyclase. The Ca2+-stimulated adenylate cyclase was purified at least 55-fold with a 13% yield.