The activity of carbonic anhydrase has been estimated by three procedures: manometric (l-3), calorimetric (2, 4-8), and electrometric (9). For investigations of the enzyme concentration of tissues the calorimetric method has often been used in preference to the manometric technique because of its relative simplicity. A disadvantage of the calorimetric method has been the inhibitory effects of t...

OBJECTIVE To report the safe and successful use of the carbonic anhydrase inhibitor acetazolamide for treatment of patients with episodic ataxia and periodic paralysis who had been denied treatment because of a history of severe allergic reactions to antibiotic sulfonamides. DESIGN Case reports. SETTING University of Rochester Medical Center, Rochester, New York. PATIENTS A 61-year-old ma...

Carbonic anhydrases are mostly zinc metalloenzymes that catalyze the reversible hydration/dehydration of CO2/HCO3 (-) Previously, the X-ray crystal structures of CO2-bound holo (zinc-bound) and apo (zinc-free) human carbonic anhydrase IIs (hCA IIs) were captured at high resolution. Here, we present sequential timeframe structures of holo- [T = 0 s (CO2-bound), 50 s, 3 min, 10 min, 25 min, and 1...

CO2 H2O^ HCO3 H (Eq. 1) The first carbonic anhydrase was purified from erythrocytes in 1933 (1) followed by the characterization of several mammalian isozymes that dominated research on carbonic anhydrase until recently. Although it has been known since the 1940s that carbonic anhydrase is ubiquitous in plants (2), where it is essential for CO2 fixation, relatively few studies had been reported...

Carbonic anhydrase preparations from human erythrocytes contain at least three distinct molecular forms of the enzyme (l-4), two of which-denoted here as carbonic anhydrases B and C-have been studied in detail. They differ widely in specific activity, and also in their isoelectric points (1, 4), their amino acid composition (4-6), and their chromatographic behavior (3,4). Earlier studies on the...

iii GENERAL INTRODUCTION 1 PART 1. DECIPHERING PROTEOLYTIC PROCESSING OF PERIPLASMIC CARBONIC ANHYDRASE 1(CAH1) 9

The prototype of the gamma-class of carbonic anhydrase has been characterized from the methanogenic archaeon Methanosarcina thermophila. Previously reported kinetic studies of the gamma-class carbonic anhydrase are consistent with this enzyme having a reaction mechanism similar to that of the mammalian alpha-class carbonic anhydrase. However, the overall folds of these two enzymes are dissimila...

Mosquito larvae use a digestive strategy that is relatively rare in nature. The anterior half of the larval mosquito midgut has a luminal pH that ranges between 10.5 and 11.5. Most other organisms, both large and small, initiate digestion in an acid medium. The relative uniqueness of the highly alkaline digestive strategy has been a long-standing research focus in larval lepidopterans. More rec...