Determination of Lysine pK Values Using [5-~(13)C]Lysine:Application to the Lyase Domain of DNA Pol beta

摘要

Determination of the protonation state of titratable protein residues is of critical importance for the interpretation of active site chemistry,as well as for understanding the role of electrostatic interactions in protein folding and stability.NMR spectroscopy provides the most powerful approach available for the determination of pK values for individual protein residues,particularly in combination with isotopic labeling strategies.Nevertheless,the limited pH stability range of most proteins poses a significant obstacle to obtaining reliable pK values based on the pH dependence of resonance shifts.