Neutron structure of human carbonic anhydrase II: a hydrogen-bonded water network "switch" is observed between pH 7.8 and 10.0.
PubMed id: 21988105
The neutron structure of wild-type human carbonic anhydrase II at pH 7.8 has
been determined to 2.0 Å resolution. Detailed analysis and comparison to the
previously determined structure at pH 10.0 show important differences in the
protonation of key catalytic residues in the active site as well as a
rearrangement of the H-bonded water network. For the first time, a completed
H-bonded network stretching from the Zn-bound solvent to the proton shuttling
residue, His64, has been directly observed.