CARBONIC ANHYDRASE ISOZYMES OF NEONATAL AND ADULT HUMAN AND SOME ANIMAL ERYTHROCYTES.

Abstract

SummaryIon exchange separations utilizing DEAE‐cellulose are described that are capable of isolating carbonic anhydrases individually or in groups as they occur in bovine, guinea pig, adult human, or neonatal human erythrocytes.Acrylamide gel electrophoresis procedures have been utilized for evaluation of purification processes as well as for demonstration of relative carbonic anhydrase activities of the various enzymes and for estimation of their esterase activities.Guinea pig carbonic anhydrases, similar to those from human erythrocytes, have both high and low specific activity forms, while the bovine enzymes demonstrate no such difference in activity.The pattern of the neonatal resembles that of the major adult human carbonic anhydrases; a reduction in activity, however, is apparent for the principal high activity form of the enzyme. The total recoverable enzyme as well as the measurable activity is lower in neonatal than adult erythrocytes.The active carbonic anhydrases in the three species studied have esterase activities independent of carbonic anhydrase activity but approximately proportional to protein concentration. Inasmuch as these enzymes hydrolyze napthyl acetates but are very inactive toward α‐napthyl propionate, α‐napthyl butyrate, or higher napthyl esters, they may be identified as acetyl esterases. They are, however, not sensitive to eserine.