Chemical cross-linking and H/D exchange for fast refinement of protein crystal structure.

A combination of chemical cross-linking and hydrogen-deuterium exchange coupled to high resolution mass spectrometry was used to describe structural differences of NKR-P1A receptor. The loop region extended from the compact core in the crystal structure was found to be closely attached to the protein core in solution. Our approach has potential to refine protein structures in solution within a few days and has very low sample consumption.