Pyrrole Hydrogen Ionization of Imidazole Derivatives in Metal Ion Complexes and Carbonic Anhydrase

1 November 1974

journal article
Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences

Vol. 71 (11) , 4346-4347
https://doi.org/10.1073/pnas.71.11.4346

Abstract

Zinc ion-induced pyrrole hydrogen ionization from a histidyl residue has recently been suggested as the source of the activity-related deprotonation in carbonic anhydrase (EC 4.2.1.1; carbonate hydro-lyase) occurring at pH 7-8. The results offered to support the hypothesis are shown to be deficient. Examination of the literature reveals no precedent for such a pronounced acidification from pK(a) [unk] 14.2 in imidazole compounds by zinc ion. It is suggested that Zn(II)-induced pyrrole ionizations in imidazoles occur with pK(a) about 13.

Keywords

This publication has 3 references indexed in Scilit:

The Activity-Related Ionization in Carbonic Anhydrase
Proceedings of the National Academy of Sciences, 1974
Crystal Structure of Human Carbonic Anhydrase C
Nature New Biology, 1972
The proton dissociation constant of pyrrole, indole and related compounds
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