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Basic muscle protein, a third genetic locus isoenzyme of carbonic anhydrase?

1977; Elsevier BV; Volume: 76; Issue: 1 Linguagem: Inglês

10.1016/0006-291x(77)91686-2

1090-2104

Martha K. Koester, Adele M. Register, Ernst A. Noltmann,

Cholinesterase and Neurodegenerative Diseases

Rabbit muscle cytosol extract contains a basic protein which represents about 2% of the total cytosol protein. It contains zinc in a 1:1 stoichiometric ratio, based on a molecular weight of 30,000, and it catalyzes the hydration of CO2. It is immunochemically distinct from the high and low activity forms of rabbit blood carbonic anhydrase. It has comparatively poor activity as an esterase, and about 20% of the CO2 hydratase activity of the rabbit blood low activity carbonic anhydrase. This CO2 hydratase activity is not inhibited by acetazolamide at concentrations which totally inhibit the activity of the blood carbonic anhydrases. The evidence obtained to date, though circumstantial, suggests that this basic metalloprotein is a carbonic anhydrase derived from a third genetic locus with properties considerably different from those of the mammalian carbonic anhydrases heretofore identified.