Covalent Inhibition Irreversible or covalent inhibition involves chemical modification of the protein. Changing pH can increase or decrease the rate. This pH-rate profile suggests that a deprotonated histidine is involved in the catalytic step. This pH-rate profile suggests that a protonated lysine is involved in the catalytic step. Note that the apparent pKa derived from inspection of kinetic data may be significantly different than the actual pKa of the sidechain.
More sophisticated analysis is required to obtain an accurate estimation of the pKa in the enzyme.
All rights reserved.