LACK OF ASSOCIATION OF G-PROTEIN BETA(2)- AND GAMMA(2)-SUBUNIT N-TERMINAL FRAGMENTS PROVIDES EVIDENCE AGAINST THE COILED-COIL MODEL OF SUBUNIT-BETA-GAMMA ASSEMBLY

摘要

The association between peptides from bovine G-protein beta(2)- and gamma(2)-subunits was studied by CD spectroscopy and cross-linking. Both peptides had similar to 25% stable alpha-helical structure at 25 degrees C, but there was no increase on mixing subunits as expected for coiled-coil formation. Also, disulphide cross-linking gave more beta(2) beta(2) homodimer than beta(2) gamma(2) heterodimer, These data do not support the proposed N-terninal coiled-coil model of beta gamma-subunit association. [References: 26]