Fig. 1. Mass spectrometric analysis of Gαs. Native or recombinant Gαs was in-gel digested and the resulting peptides analysed by MALDI-MS. Mass peaks with m/z 973.5 and 735.3 corresponded to the palmitoylated and non-palmitoylated N-terminal sequence G2CLGNSK of Gαs, respectively. (A) LC chromatogram recorded for the native protein at m/z 973.5 and the recombinant protein at m/z 735.3. (B) MS/MS spectrum of m/z = 973.58 of native Gαs. Relevant ions were labelled according to the accepted nomenclature and listed in Table II.