Oligomerization of peptides analogous to the cytoplasmic domains of coatomer receptors revealed by mass spectrometry.

摘要: Members of the p24 family type I transmembrane proteins are involved in budding coat protein (COPI)-coated vesicles. They serve as receptors, binding via their cytoplasmic domains to coatomer, a stable cytosolic complex that represents major component these Experimental evidence suggest p23, member family, binds coatomer an oligomeric state and this triggers polymerization protein. Toward understanding process at molecular level, formation noncovalent complexes relative stabilities were analyzed by Fourier transform ion cyclotron resonance mass spectrometry using nanoelectrospray ionization. Specificity stability oligomers formed established depend on characteristic peptide sequence motifs confirmed spectrometric competition experiments with control peptides. Mutations caused decreased interaction destabilization complexes. The dimeric tetrameric assessed be tails receptors. direct identification provided correlates well biochemical results. Thus, electrospray ionization proves powerful tool investigate physiologically relevant