The Carbonic Anhydrases. Questo articolo non è disponibile.The Carbonic Anhydrases

As we approach the twenty-first century the problems of industrialization are evident: we find there is a greenhouse effect, the ozone layer is being depleted, the rain is acidified, and there is a terrible problem of increasing C0 concentrations in the atmo­ 2 sphere. The carbonic anhydrases are a unique family of enzymes that solve these problems in the human body: they are responsible for converting C0 (a gas) to 2 HC0-, which is the biggest intracellular buffer, with a concomitant decrease in a 3 hydroxyl ion. Globally, the functions of the carbonic anhydrases in photosynthesis in rain forests and in the algae and plankton that cover our oceans indicate that they are also of utmost importance in the maintenance of the acid-base balance on our planet. Although the whole field of C0 metabolism is enormous and still rapidly 2 expanding, because of the research interests of the editors this book is mainly concerned with mammalian carbonic anhydrases. However, if the interested reader intends to purify carbonic anhydrases from nonmammalian sources, Dr. Cheg­ widden has provided the necessary information in Chapter 7. The carbonic anhydrases were first discovered in 1933; until1976 there were thought to be only two isozymes. Since then CA ill, IY, V, VI, and Vll have been discovered and well characterized. There is, of course, no reason to believe that we have found them all.

I. The Carbonic Anhydrase Isozymes.- 1. The Carbonic Anhydrases: Overview of Their Importance in Cellular Physiology and in Molecular Genetics.- 2. Structure and Evolutionary Origins of the Carbonic Anhydrase Multigene Family.- 3. X-Ray Crystallographic Studies of Carbonic Anhydrase Isozymes I, II, and III.- 4. Carbonic Anhydrase Kinetics and Molecular Function.- 5. Carbonic Anhydrases in Mammalian Cell Culture and Tumors.- 6. Methods for the Measurement of Carbonic Anhydrase Activity.- II. Carbonic Anhydrase Analysis.- 7. Purification of the Carbonic Anhydrases.- 8. Techniques for Measuring Carbonic Anhydrase Activity in Vitro: The Electrometric Delta pH and pH Stat Methods.- 9. Modified Micromethod for Assay of Carbonic Anhydrase Activity.- 10. Localization of Carbonic Anhydrase by Chemical Reactions.- 11. Localization of the Carbonic Anhydrases by Immunocytochemistry.- 12. Immunological Methods for Detection and Quantification of Carbonic Anhydrase Isozymes.- III. Carbonic Anhydrases in Clinical Medicine.- 13. Carbonic Anhydrase Inhibitors in Ophthalmology.- 14. The Eye: Topical Carbonic Anhydrase Inhibitors.- 15. Carbonic Anhydrase II Deficiency Syndrome: Clinical Delineation, Interpretation, and Implications.- IV. Genetic Regulation of the Carbonic Anhydrase Isozymes.- 16. The Structure and Regulation of the Human Carbonic Anhydrase I Gene.- 17. Expression of Carbonic Anhydrases I and II in Mouse Erythropoiesis.- 18. Structure and Expression of the Carbonic Anhydrase III Gene.- V. Muscle Carbonic Anhydrases.- 19. Muscle Carbonic Anhydrases: Function in Muscle Contraction and in the Homeostasis of Muscle pH and pCO2.- 20. Distribution and Ultrastructural Localization of Carbonic Anhydrase III in Different Skeletal Muscle Fiber Types.- 21. Hormonal and Neuronal Control of Carbonic Anhydrase III Gene Expression in Skeletal Muscle.- 22. Skeletal Muscle Mitochondrial Carbonic Anhydrase: A Case of Species Specificity.- VI. Carbonic Anhydrases of the Gastrointestinal Tract.- 23. Distribution and Functions of Carbonic Anhydrase in the Gastrointestinal Tract.- 24. Hormonal Regulation and Localization of Rat Liver Carbonic Anhydrase.- 25. Liver Mitochondrial Carbonic Anhydrase (CA V), Gluconeogenesis, and Ureagenesis in the Hepatocyte.- VII. The Carbonic Anhydrases of Other Organs.- 26. Function and Regulation of the Carbonic Anhydrases in the Vertebrate Neural Retina.- 27. Carbonic Anhydrase and Sensory Function in the Central Nervous System.- 28. Carbonic Anhydrase in Myelin and Glial Cells in the Mammalian Central Nervous System.- 29. Lung Carbonic Anhydrase.- 30. Carbonic Anhydrase and Chemoreception in Carotid and Aortic Bodies.- 31. Carbonic Anhydrases in the Kidney.- 32. Localization of Carbonic Anhydrase Isozymes in Calcified Tissues.- 33. Carbonic Anhydrase and Skeletogenesis.- 34. Carbonic Anhydrases Secreted in the Saliva.