An artificial metathesase results from incorporation of an Hoveyda-Grubbs catalyst bearing an arylsulfonamide anchor within human carbonic anhydrase II. The optimization of the catalytic performance is achieved upon combining both chemical and genetic means. Up to 28 TONs were obtained within four hours under aerobic physiological conditions.

This paper describes the estimation of binding constants (Kb) between carbonic anhydrase B (CAB, EC 4.2.1.1, from bovine erythrocytes) and charged benzenesulfonamides by affinity capillary electrophoresis (ACE) under conditions in which the migration time is affected by changes in electroosmotic flow and by nonspecific interactions accompanying changes in the concentration of ligand. Comparison...

The denaturation and renaturation of bovine carbonic anhydrase B is a thermodynamically reversible process, uncomplicated by aggregation or disuhide bond formation. The reaction is less cooperative than is the unfolding and refolding of most globular proteins, in that distinct successive stages can be observed both in equilibrium and kinetic measurements. This enzyme is therefore ideally suited...

A synthetic mimic of carbonic anhydrase shows a lower p K value for the zinc-bound water than natural enzyme. As result, it is able to hydrolyze nonactivated esters at pH 7.

Acetate assimilation in C. reinhardtii leads to bicarbonate and CO2 aq formation in heterotrophic growth condition. Bicarbonate and CO2 aq thus formed under this condition remain in equilibrium with the action of carbonic anhydrases. Carbonic anhydrase catalyzes reversible hydration of carbon dioxide and dehydration of bicarbonate. In this article we report that the rapid exchange catalyzed by ...

cDNA clones for rat muscle carbonic anhydrase III have been isolated from a lambda gt-11 library and sequenced. Comparison with human CAIII cDNA showed about 90% homology to rat. The rat clones were used to estimate mRNA from liver and muscle on Northern blots and showed that the sexual dimorphism of CAIII in rat liver relates to a difference in mRNA levels.

Human carbonic anhydrase B loses enzymatic activity as it undergoes an irreversible conformational change near pH 4 (1). Riddiford (2) further found that seven of the eleven histidyl groups, which are unreactive in the native protein, become titratable during this change. Also, five or six of the eight tyrosyl groups do not ionize freely and reversibly in the native protein (2, 3). Human carbon...

The reversible complex between the metalloenzyme bovine carbonic anhydrase B and the sulfonamide inhibitor acetazolamide can be "frozen" irreversibly by the addition of a covalent bond between the methyl group of the inhibitor and the tau-nitrogen of histidine-64. In both cases the inhibited enzyme is inactive as an esterase toward p-nitrophenyl propionate at physiological pH but retains activi...

The morphological and cytochemical changes in erythroid-cell differentiation have been extensively studied: application of the velocity-sedimentation technique has provided preliminary data on the associated biochemical changes (Denton & Arnstein, 1973). After the last cell division there is a dramatic increase in the synthesis of haemoglobin which, at least in part, probably accounts for the a...