Carbonic Anhydrase II: A cytosolic carbonic anhydrase isoenzyme found widely distributed in cells of almost all tissues. Deficiencies of carbonic anhydrase II produce a syndrome characterized by OSTEOPETROSIS, renal tubular acidosis (ACIDOSIS, RENAL TUBULAR) and cerebral calcification. EC 4.2.1.-Carbonic Anhydrases: A family of zinc-containing enzymes that catalyze the reversible hydration of carbon dioxide. They play an important role in the transport of CARBON DIOXIDE from the tissues to the LUNG. EC 126.96.36.199.Carbonic Anhydrase Inhibitors: A class of compounds that reduces the secretion of H+ ions by the proximal kidney tubule through inhibition of CARBONIC ANHYDRASES.Carbonic Anhydrase III: A cytosolic carbonic anhydrase isoenzyme primarily expressed in skeletal muscle (MUSCLES, SKELETAL). EC 4.2.1.-Ethoxzolamide: A carbonic anhydrase inhibitor used as diuretic and in glaucoma. It may cause hypokalemia.Acetazolamide: One of the CARBONIC ANHYDRASE INHIBITORS that is sometimes effective against absence seizures. It is sometimes useful also as an adjunct in the treatment of tonic-clonic, myoclonic, and atonic seizures, particularly in women whose seizures occur or are exacerbated at specific times in the menstrual cycle. However, its usefulness is transient often because of rapid development of tolerance. Its antiepileptic effect may be due to its inhibitory effect on brain carbonic anhydrase, which leads to an increased transneuronal chloride gradient, increased chloride current, and increased inhibition. (From Smith and Reynard, Textbook of Pharmacology, 1991, p337)Carbonic Anhydrase I: A cytosolic carbonic anhydrase isoenzyme primarily expressed in ERYTHROCYTES, vascular endothelial cells, and the gastrointestinal mucosa. EC 4.2.1.-Carbonic Anhydrase IV: A membrane-bound carbonic anhydrase found in lung capillaries and kidney.Methazolamide: A carbonic anhydrase inhibitor that is used as a diuretic and in the treatment of glaucoma.Acidosis, Renal Tubular: A group of genetic disorders of the KIDNEY TUBULES characterized by the accumulation of metabolically produced acids with elevated plasma chloride, hyperchloremic metabolic ACIDOSIS. Defective renal acidification of URINE (proximal tubules) or low renal acid excretion (distal tubules) can lead to complications such as HYPOKALEMIA, hypercalcinuria with NEPHROLITHIASIS and NEPHROCALCINOSIS, and RICKETS.Osteopetrosis: Excessive formation of dense trabecular bone leading to pathological fractures; OSTEITIS; SPLENOMEGALY with infarct; ANEMIA; and extramedullary hemopoiesis (HEMATOPOIESIS, EXTRAMEDULLARY).Bicarbonates: Inorganic salts that contain the -HCO3 radical. They are an important factor in determining the pH of the blood and the concentration of bicarbonate ions is regulated by the kidney. Levels in the blood are an index of the alkali reserve or buffering capacity.Benzolamide: Selective renal carbonic anhydrase inhibitor. It may also be of use in certain cases of respiratory failure.Carbon Dioxide: A colorless, odorless gas that can be formed by the body and is necessary for the respiration cycle of plants and animals.Carbonic Acid: Carbonic acid (H2C03). The hypothetical acid of carbon dioxide and water. It exists only in the form of its salts (carbonates), acid salts (hydrogen carbonates), amines (carbamic acid), and acid chlorides (carbonyl chloride). (From Grant & Hackh's Chemical Dictionary, 5th ed)Isoenzymes: Structurally related forms of an enzyme. Each isoenzyme has the same mechanism and classification, but differs in its chemical, physical, or immunological characteristics.Hydrogen-Ion Concentration: The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH = log 1/2[1/(H+)], where (H+) is the hydrogen ion concentration in gram equivalents per liter of solution. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Dansyl Compounds: Compounds that contain a 1-dimethylaminonaphthalene-5-sulfonyl group.Sodium-Bicarbonate Symporters: Proteins that cotransport sodium ions and bicarbonate ions across cellular membranes.Zinc: A metallic element of atomic number 30 and atomic weight 65.38. It is a necessary trace element in the diet, forming an essential part of many enzymes, and playing an important role in protein synthesis and in cell division. Zinc deficiency is associated with ANEMIA, short stature, HYPOGONADISM, impaired WOUND HEALING, and geophagia. It is known by the symbol Zn.Crystallography, X-Ray: The study of crystal structure using X-RAY DIFFRACTION techniques. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Models, Molecular: Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.Histidine: An essential amino acid that is required for the production of HISTAMINE.Protons: Stable elementary particles having the smallest known positive charge, found in the nuclei of all elements. The proton mass is less than that of a neutron. A proton is the nucleus of the light hydrogen atom, i.e., the hydrogen ion.Kinetics: The rate dynamics in chemical or physical systems.Catalysis: The facilitation of a chemical reaction by material (catalyst) that is not consumed by the reaction.Catalytic Domain: The region of an enzyme that interacts with its substrate to cause the enzymatic reaction.Pancreatitis, Alcoholic: Acute or chronic INFLAMMATION of the PANCREAS due to excessive ALCOHOL DRINKING. Alcoholic pancreatitis usually presents as an acute episode but it is a chronic progressive disease in alcoholics.Protein Denaturation: Disruption of the non-covalent bonds and/or disulfide bonds responsible for maintaining the three-dimensional shape and activity of the native protein.Anion Exchange Protein 1, Erythrocyte: A major integral transmembrane protein of the ERYTHROCYTE MEMBRANE. It is the anion exchanger responsible for electroneutral transporting in CHLORIDE IONS in exchange of BICARBONATE IONS allowing CO2 uptake and transport from tissues to lungs by the red blood cells. Genetic mutations that result in a loss of the protein function have been associated with type 4 HEREDITARY SPHEROCYTOSIS.Protein Conformation: The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).Carbonic Anhydrase V: A carbonic anhydrase isoenzyme found in MITOCHONDRIA where it provides bicarbonate ions that are components in the urea cycle and in GLUCONEOGENESIS.Sulfonamides: A group of compounds that contain the structure SO2NH2.EsterasesAcroleinOncogene Proteins v-erbA: Transforming proteins encoded by erbA oncogenes from the avian erythroblastosis virus. They are truncated versions of c-erbA, the thyroid hormone receptor (RECEPTORS, THYROID HORMONE) that have retained both the DNA-binding and hormone-binding domains. Mutations in the hormone-binding domains abolish the transcriptional activation function. v-erbA acts as a dominant repressor of c-erbA, inducing transformation by disinhibiting proliferation.Water: A clear, odorless, tasteless liquid that is essential for most animal and plant life and is an excellent solvent for many substances. The chemical formula is hydrogen oxide (H2O). (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Hydrogen Bonding: A low-energy attractive force between hydrogen and another element. It plays a major role in determining the properties of water, proteins, and other compounds.Erythrocytes: Red blood cells. Mature erythrocytes are non-nucleated, biconcave disks containing HEMOGLOBIN whose function is to transport OXYGEN.Binding Sites: The parts of a macromolecule that directly participate in its specific combination with another molecule.Protein Folding: Processes involved in the formation of TERTIARY PROTEIN STRUCTURE.Cattle: Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.Antiporters: Membrane transporters that co-transport two or more dissimilar molecules in the opposite direction across a membrane. Usually the transport of one ion or molecule is against its electrochemical gradient and is "powered" by the movement of another ion or molecule with its electrochemical gradient.Enzyme Stability: The extent to which an enzyme retains its structural conformation or its activity when subjected to storage, isolation, and purification or various other physical or chemical manipulations, including proteolytic enzymes and heat.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.