Anionic inhibitors, recognition

Water molecules or anions close to the active sites in the protease enzymes, mentioned above, may not be considered circumstantial, but may effectively contribute to the removal of the surplus proton from the imidazolium cation before the actual catalytic event. They could serve well to create the initial ion/neutral form of the Aspl02-His57 couple which is important for the initial step of the catalytic process in most discussions 11611 .13i. such a proton removal may be caused by the productive binding of a true substrate (or inhibitor) of the enzyme to the neighboring recognition clefts of the active site. 

Molybdate s low toxicity to fish and other aquatic life has helped to gain recognition in recent years as a corrosion inhibitor. Molybdate forms its protective film by adsorption on metal surfaces. When chloride and sulfate anions are present in the cooling water environment, they compete for adsorption, and high concentrations of molybdate are needed for effective passivation of the metal surfaces. In order to be able to reduce the molybdate concentration for cost-effective levels, synergistic blends are made up that include other inhibitors such as phosphorates and zinc. 

A schematic of the structure of the thrombin molecule is presented in Figure 2. The important binding sites on the surface of the thrombin molecule include the catalytic site and two exosites (anionic and apolar) or substrate recognition sites. Whereas the catalytic site is responsible for the serine protease activity, the separate substrate recognition sites are involved in the binding of heparin, fibrinogen, and thrombomodulin (6). These sites serve as targets for the direct thrombin inhibitors,... 

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