Hi, you may also look into the papers of John A. Gerlt, who did a lot on protonabtraction reactions and the theory behind this. Esspecially the pKa disturbance and the match to the pkA of the substrate of the reaction.
Best Wishes Christian Am Dienstag 07 Februar 2012 12:48:26 schrieb Deepak Oswal: > Dear colleagues, > > We have solved the crystal structure of a human enzyme. The pKa of a > catalytically critical aspartic acid has increased to 6.44. It is hydrogen > bonded (2.8 Angstroms) to a water molecule that is supposed to donate a > proton during the catalysis. Can anybody help me a) interpret the > significance of this increase in pKa of the aspartic acid from 3.8 to 6.44 > in context with the catalysis? Is this advantageous or detrimental? b) How > is pKa related to an amino acids’ ability to force a water molecule to > donate a proton? c) At pH 7.4, the aspartic acid would be de-protonated > irrespective of whether the pKa is 3.8 or 6.44; isn’t that true? d) Have > similar increase in pKa values observed for aspartic acids before? I would > be grateful if anybody could explain or comment on the above queries. > > Deepak Oswal >
