Structure and dynamics of dark-state bovine rhodopsin revealed by chemical cross-linking and high-resolution mass spectrometry.

Recent work using chemical cross-linking to define interresidue distance constraints in proteins has shown that these constraints are useful for testing tertiary structural models. We applied this approach to the G-protein-coupled receptor bovine rhodopsin in its native membrane using lysine- and cysteine-targeted bifunctional cross-linking reagents. Cross-linked proteolytic peptides of rhodopsin were identified by combined liquid chromatography and FT-ICR mass spectrometry with automated data-reduction and assignment software.

A novel protein crosslinking reagent for the determination of moderate resolution protein structures by mass spectrometry (MS3-D).

A new approach to the determination of moderate resolution protein structures, termed MS3-D-Mass Spectrometry in 3 Dimensions-has recently been disclosed. The method involves the formation of covalent crosslinks between reactive residues on the protein surface, the determination of the location of those crosslinks in primary sequence space by mass spectrometry, and then the imposition of a distance constraint upon the location of the respective side chains during distance geometry calculations of protein structure. MS3-D is rapid, requires small amounts of protein, and works in native biochemical conditions.