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Is cyanate a carbonic anhydrase substracte?
Author(s) -
Supuran Claudiu T.,
Conroy Curtis W.,
Maren Thomas H.
Publication year - 1997
Publication title -
proteins: structure, function, and bioinformatics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.699
H-Index - 191
eISSN - 1097-0134
pISSN - 0887-3585
DOI - 10.1002/(sici)1097-0134(199702)27:2<272::aid-prot12>3.0.co;2-j
Subject(s) - cyanate , thiocyanate , carbonic anhydrase , chemistry , cyanide , cobalt , active site , adduct , enzyme , molecule , hydrolysis , metal , inorganic chemistry , stereochemistry , polymer chemistry , organic chemistry
A study was undertaken to investigate whether diverse carbonic anhydrase (CA) isozymes (both native Zn as well as cobalt‐substituted) are able to catalyze the hydrolysis of anions such as cyanide, cyanate, and thiocyanate. A controversy exists between the crystallographic and spectroscopic data of CA II‐anion adducts. In the former case it has been shown that “metal poisons” such as CN − and CNO − are not directly coordinated to the active site Zn(II) ion whereas spectroscopic studies indicate otherwise. A theoretical study in the above systems did not resolve this controversy, since it was calculated that all three anions can act as CA substrates. In this paper we prove experimentally that none of them may act as substrates of CA and propose an explanation to the above controversy, discussing the mode of binding of small molecules within the enzyme active site. © 1997 Wiley‐Liss, Inc.