Article
Structural and kinetic analysis of proton shuttle residues in the active site of human carbonic anhydrase III.
Proteins - 1 Jul 2007
Elder Ileana, Fisher Zoë, Laipis Philip J, Tu Chingkuang, McKenna Robert, Silverman David N
Abstract excerpt
We report the X-ray crystal structures and rate constants for proton transfer in site-specific mutants of human carbonic anhydrase III (HCA III) that place a histidine residue in the active-site cavity: K64H, R67H, and K64H-R67N HCA III. Prior evidence from the exchange of 18O between CO2 and water measured by mass spectrometry shows each mutant to have enhanced proton transfer in catalysis compared with...
Topics
- Binding Sites
- Carbonic Anhydrase III
- Catalysis
- Crystallography, X-Ray
- Humans
- Kinetics
- Models, Molecular
- Mutation
- Protons