A high temperature transfer procedure for detection of G protein gamma subunits by immunoblotting.

The production of antibodies against synthetic peptides derived from amino acid sequences common or unique to a particular protein(s) is an important tool in the identification of structurally related members of an ever-increasing number of protein families. The successful use of anti-peptide antibodies requires that the protein(s) of interest be properly transferred and fully denatured prior to detection by Western-type immunoblotting. In this paper, we demonstrate that conventional transfer procedures are not successful in presenting the G protein gamma subunits in a suitable state for immunodetection. We describe a high temperature (70 degrees C) transfer procedure that results in a more than 20-fold enhancement in the sensitivity of immunodetection of the various G protein gamma subunits. The effect of high temperature transfer could not be duplicated by including 0.2% SDS in the buffer during transfer to nitrocellulose, or by baking or autoclaving the nitrocellulose after transfer. Thus, high temperature transfer is a powerful procedure for enhancing immunoblot detection of protein(s) that may be resistant to denaturation and/or subject to renaturation during the transfer and/or binding to nitrocellulose.