An appropriately positioned general base helps remove the proton from the serine residue hydroxyl, increasing its nucleophilicity. A lysine residue, such as Lys73 in the class A beta-lactamase catalytic network, is a plausible participant; its protonation state depends on its active-site environment and interactions with other residues. A glutamate residue, notably Glu166, also participates in proton transfer and activation of the water needed for deacylation. Efficient catalysis requires proton-transfer chemistry as well as positioning the attacking oxygen. The precise division of roles during acylation depends on the enzyme state, so the drawing alone cannot assign a complete mechanism to one residue.[ref]
Patricia S. Langan Created 2026-10-20 Updated 2026-11-05
Researcher in enzyme structural biology. Langan and collaborators used neutron and X-ray crystallography to investigate a conserved glutamate in beta-lactamase, connecting atomic positions with a proposed catalytic role.[ref]