Characterization of antibodies for various G-protein β and γ subunits

Antibodies to the β and γ subunits of G proteins have been invaluable in the investigations that have begun to dissect the structure and function of these subunits. The cDNAs for four β subunit types and for several γ subunits have now been characterized. The most useful antisera are those raised against peptides specific to the amino acid sequence encoded by cDNAs for different β and γ subunit types. Depending on the region of the protein chosen for synthesizing a corresponding peptide, these antibodies are capable of reacting with a particular subunit type specifically or with several different subunits. Of an immunoblot of a mixture of different subunit types, specific peptide antisera can distinguish among different members of the β and γ subunit families of proteins. Although the antisera are raised against a peptide corresponding to a relatively small portion of the protein, several of the antisera against the G-protein β and γ subunits are capable of immunoprecipitating the βγ complex. They can also be used for immunocytochemical localization of the β or γ subunits present in transient transfectants.