Structural and Kinetic Characterization of Active-Site Histidine as a Proton Shuttle in Catalysis by Human Carbonic Anhydrase II
Fisher, Z., Hernandez Prada, J.A., Tu, C.K., Duda, D., Yoshioka, C., An, H., Govindasamy, L., Silverman, D.N., McKenna, R.(2005) Biochemistry 44: 1097-1105
- PubMed: 15667203 
- DOI: 10.1021/bi0480279
- Primary Citation of Related Structures:  
1T9N, 1TB0, 1TBT, 1TE3, 1TEQ, 1TEU, 1TG3, 1TG9, 1TH9, 1THK - PubMed Abstract: 
In the catalysis of the hydration of carbon dioxide and dehydration of bicarbonate by human carbonic anhydrase II (HCA II), a histidine residue (His64) shuttles protons between the zinc-bound solvent molecule and the bulk solution. To evaluate the effect of the position of the shuttle histidine and pH on proton shuttling, we have examined the catalysis and crystal structures of wild-type HCA II and two double mutants: H64A/N62H and H64A/N67H HCA II ...