Updated Protocols and Comments on the Purification without Use of Activating Ligands of the Coupling Proteins Nsand Niof the Hormone Sensitive Adenylyl Cyclase

Ns and Ni have been purified without using NaF and Mg as stabilizing agents (Codina, J., Hildebrandt, J.D., Sekura, R.D., Birnbaumer, M., Bryan, J., Manclark, C.R. and Birnbaumer, L. [1984] J. Biol. Chem. 259, in press). Since the submission of that report, several modifications have been introduced to the purification procedure and additional fractions have been processed from which N proteins are obtained. This article describes the updated protocols and presents methodological details not included in the previous publication. The final products are Ns, the stimulatory N, Ni the inhibitory N, both of subunit structure alpha beta gamma, and a Mr = 40,000 protein of beta gamma composition. They are obtained from human erythrocytes.