title: Effects of pH and inhibitors on the absorption spectrum of cobalt(II)-substituted carbonic anhydrase III from bovine skeletal muscle.
abstract: Bovine apocarbonic anhydrase III has been prepared by incubation with 2-carboxy-1,10-phenanthroline at pH 5.5. The Co(II)-substituted enzyme has been prepared and its absorption spectrum has been studied. The spectrum is nearly pH-independent above pH 6. It is very similar to the high pH spectral forms of Co(II)-carbonic anhydrases I and II. The spectra of complexes with the sulfonamide inhibitor, acetazolamide, and with CN- and NCO - are virtually identical to the spectra of the corresponding complexes with Co(II)-isoenzymes I and II. The spectrum of the N-3 complex indicates that this anion is bound somewhat differently in Co(II) isoenzyme III than in the other Co(II)-substituted isoenzymes.
mesh_terms: D000818:Animals; D002021:Buffers; D002257:Carbonic Anhydrase Inhibitors / Q000494:pharmacology*; D002256:Carbonic Anhydrases / Q000378:metabolism*; D002417:Cattle; D002614:Chelating Agents; D003035:Cobalt; D006863:Hydrogen-Ion Concentration; D007527:Isoenzymes / Q000378:metabolism*; D009132:Muscles / Q000201:enzymology*; D010618:Phenanthrolines; D013053:Spectrophotometry; D015032:Zinc
chemical_list: D002021:Buffers; D002257:Carbonic Anhydrase Inhibitors; D002614:Chelating Agents; D007527:Isoenzymes; D010618:Phenanthrolines; C041484:1,10-phenanthroline-2-carboxylic acid; D003035:Cobalt; D002256:Carbonic Anhydrases; D015032:Zinc