Isolation of homologous and heterologous complexes between catalytic and regulatory components of adenylate cyclase by forskolin-Sepharose.

Homologous and heterologous complexes between catalytic and GTP-binding components can be isolated by means of immobilized succinyldeacetylforskolin (forskolin-Sepharose). A heterologous complex is formed by reconstitution of forskolin-Sepharose bound catalytic function from rabbit myocardial membranes with the homogenous [3H]methyl-GTP-binding protein from duck erythrocyte membranes. Analysis of the reconstituted complex by sodium dodecyl sulfate polyacrylamide gelelectrophoresis reveals that only the Mr 42 000 component of the GTP-binding protein's Mr 42 000/Mr 35 000 heterodimer contributes to the formation of active adenylate cyclase.