The Carbonic Anhydrases

Carbonic anhydrase (CA) is a seemingly ubiquitous enzyme of profound physiological importance, which plays essential roles in respiration, acid-base homeostasis, bone resorption, calcification, photosynthesis, several biosynthetic pathways and a variety of processes involving ion, gas and fluid transfer. This enzyme, which is present in at least three gene families (a, ß, ?), has found favour as a model for the study of evolution of gene families and for site-directed mutagenesis in structure/function relationships, for protein folding and for transgenic and gene target studies. Since the early use of CA inhibitors as diuretics and in treating congestive heart failure, the enzyme has been target of considerable clinical attention. Much of this is now focused on endeavours to produce a new generation of such drugs for the effective treatment of glaucoma and other potential applications. Recent data, suggesting links between CA and various disease processes, including cancer, have stimulated further...

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.

The study of carbonic anhydrase has spanned multiple generations of scientists. Carbonic anhydrase was first discovered in 1932 by Meldrum and Roughton. Inhibition by sulfanilamide was shown in 1940 by Mann and Keilin. Even Hans Krebs contributed to early studies with a paper in 1948 showing the relationship of 25 different sulfonamides to CA inhibition. It was he who pointed out the importance of both the charged and uncharged character of these compounds for physiological experiments. The field of study that focuses on carbonic anhydrase (CA) has exploded in recent years with the identification of new families and isoforms. The CAs are metalloenzymes which are comprised of 5 structurally different families: the alpha, beta, gamma, and delta, and epsilon classes. The alpha class is found primarily in animals with several isoforms associated with human disease. The beta CAs are expressed primarily in plants and are the most divergent. The gamma CAs are the most ancient. These are structurally related to the beta CAs, but have a mechanism more similar to the alpha CAs. The delta CAs are found in marine algae and diflagellates. The epsilon class is found in prokaryotes in which it is part of the carboxysome shell perhaps supplying RuBisCO with CO2 for carbon fixation. With the excitement surrounding the discovery of disease-related CAs, scientists have redoubled their efforts to better understand structure-function relationships, to design high affinity, isotype-specific inhibitors, and to delineate signaling systems that play regulatory roles over expression and activity. We have designed the book to cover basic information of mechanism, structure, and function of the CA families. The authors included in this book bring to light the newest data with regard to the role of CA in physiology and pathology, across phylums, and in unique environmental niches.

This book offers deep insights into the thermodynamics and molecular structures of the twelve catalytically active isoforms of human carbonic anhydrase (CA) with a particular focus on inhibitor binding for drug design. X-ray crystallographic structures in combination with enzyme kinetic testing provide information on the interaction of CAs and their inhibitors, knowledge which is crucial for rational drug design. CAs are zinc carrying enzymes that catalyse the reversible interconversion of carbon dioxide and bicarbonate and are involved in numerous cellular processes. They are therefore a common target for drugs. The suppression of CA activities through inhibitory compounds has found application for example in diuretics and in glaucoma therapy. In this book methods used to determine binding thermodynamics of inhibitory compounds (Isothermal titration calorimetry, Fluorescent thermal shift assay/differential scanning fluorimetry and others) will be compared in detail. Also types and chemical synthesis of CA inhibitors, the use of antibodies against CAs as well as inhibitor application in animals are discussed.

This volume assembles and integrates the wealth of diverse information that is now accumulating in this burgeoning field. The existing and potential therapeutic applications of targeting CA cover a remarkably wide-range of diseases and disorders and have generated increasing and extensive interest in recent years. Its inter-disciplinary approach embraces both the most up-to-date therapeutic application of CA-targeting and the latest research data that will provide a platform for the development of novel applications. The interested audience comprises scientists and clinicians from many relevant disciplines within science and medicine.

Carbonic Anhydrase: Its Inhibitors and Activators provides a state-of-the-art overview of the latest developments and challenges in carbonic anhydrase research. Authors describe the mechanisms of action of specific inhibitors in relation to physiological function, and present previously unpublished research on CA activators. Written by a team of in

Carbonic anhydrases (CAs, EC 4.2.1.1) are ubiquitous metalloenzymes, present throughout most living organisms and encoded by five evolutionarily unrelated gene families. The Carbonic Anhydrases as Biocatalysts: From Theory to Medical and Industrial Applications presents information on the growing interest in the study of this enzyme family and their applications to both medicine and biotechnology. Offers comprehensive coverage of the carbonic anhydrases enzyme family and their properties as biocatalysts Includes current applications of carbonic anhydrases in biotechnology on the basis of their catalytic efficiency, including new technologies for CO2 capture processes Identifies new targets for drug design studies Provides a selectivity profile for the different carbonic anhydrases and their related biomedical applications

Carbonic Anhydrases provides an interdisciplinary review of the burgeoning carbonic anhydrase (CA) research area, spanning from CAs classification (biochemical and structural features) to drug design and pharmacology of CA inhibitors and activators, finally touching on the biotechnological applications of these metalloenzymes. The book adopts a clear step-by-step approach and introduction to this intricate and highly interdisciplinary field. A diverse range of chapters from international experts speak to CA classification and distribution, the mechanisms of action and drug design of inhibitors and activators, the druggability of the various isoforms in the treatment of a multitude of diseases, and threats to human health. Carbonic Anhydrases provides biology, biochemistry, and medicinal chemistry students and researchers a thorough discussion and update on the evergreen and expanding research area of CAs. ● Offers a full overview of CAs' biochemical and structural features, as well as drug design and pharmacology of inhibitors and activators. ● Provides a thorough update on the newly identified isoforms, modulating chemotypes, and innovative biomedical applications. ● Describes the current biotechnological applications of CAs, including processes for CO2 capture. ● Features chapter contributions from international leaders in CA biology, medicinal chemistry, and pharmacology.