Publication Abstract from PubMed
The structure of the Asn102 mutant of trypsin was determined in order to distinguish whether the reduced activity of the mutant at neutral pH results from an altered active site conformation or from an inability to stabilize a positive charge on the active site histidine. The active site structure of the Asn102 mutant of trypsin is identical to the native enzyme with respect to the specificity pocket, the oxyanion hole, and the orientation of the nucleophilic serine. The observed decrease in rate results from the loss of nucleophilicity of the active site serine. This decreased nucleophilicity may result from stabilization of a His57 tautomer that is unable to accept the serine hydroxyl proton.
The three-dimensional structure of Asn102 mutant of trypsin: role of Asp102 in serine protease catalysis.,Sprang S, Standing T, Fletterick RJ, Stroud RM, Finer-Moore J, Xuong NH, Hamlin R, Rutter WJ, Craik CS Science. 1987 Aug 21;237(4817):905-9. PMID:3112942[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
