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[Genetic independence of two forms of carbonic anhydrase from bovine erythrocytes]
Insights
Bovine erythrocyte carbonic anhydrase exists as two main genetic variants, CI and CII, differing in primary structure. Their inheritance patterns in heterozygous individuals show significant variability.
Area of Science:
- Biochemistry
- Enzymology
- Genetics
Context:
- Carbonic anhydrases are crucial enzymes in various physiological processes.
- Bovine erythrocytes contain distinct carbonic anhydrase isozymes.
- Understanding isozyme variations aids in comprehending enzyme function and inheritance.
Purpose:
- To separate and isolate bovine carbonic anhydrase isozymes CI and CII.
- To characterize the relationship between isozymes CI, CII, and the minor component CIv1.
- To investigate the inheritance patterns of bovine carbonic anhydrase isozymes.
Summary:
- Two major bovine erythrocyte carbonic anhydrase isozymes, CI and CII, were separated using ion-exchange chromatography (DEAE-cellulose and DEAE-sephadex A-50).
- DEAE-sephadex A-50 effectively isolated pure CII, separating it from CIv1.
- CIv1 appears to be a conformational variant of CI, while CI and CII are genetic variants differing by a specific amino acid substitution (Arg to Gln).
Impact:
- Elucidates the structural differences between bovine carbonic anhydrase isozymes.
- Provides insights into the genetic basis and inheritance of carbonic anhydrase polymorphism in cattle.
- Contributes to the understanding of enzyme variation and its implications in biological systems.
Abstract:
The two major forms of bovine erythrocyte carbonic anhydrase have been designated as CI and CII because their high activity of the C type. Separation of both forms and isolation of CI from the ethanol chloroform extract of the hemolysate were obtained by either column chromatography on DEAE-cellulose DE 23 or on DEAE-sephadex A-50. But pure preparations of the CII form were only obtained from DEAE-sephadex A-50 which separated CII from a minor component CIv1. Comparative studies of the CI and CII forms and of the minor component CIv1 strongly suggest that CIv1 is a conformational variant of CI and CII are genetic variants differing at least in their primary structure by one Arg yields Gln substitution 56 residues from the N-acetylated terminus. Based on the large variability of the proportion of the two isozymes in heterozygous individuals, the modality of the inheritance of these enzymes is discussed.