With no further introduction let me start with a new topic. The topic chosen is ENZYME INHIBITORS. Enzyme inhibitors are the substances that lower the catalytic action of enzymes. Enzyme inhibition may be Competitive Uncompetitive Non competitive Competitive Inhibition: This phenomenon can be observed if both substrate and inhibitor compete for the same active site (binding site) of the enzyme. However this can be reversed by increasing the substrate concentration. Uncompetitive Inhibition: Here the inhibitor binds to a particular site which is available only when the substrate (S1) binds to the active site of the enzyme. This inhibition is seen during multi substrate reactions where the inhibitor is uncompetitive with respective to one substrate (S1) but competitive with respective to another substrate (S2).  Non competitive Inhibition: Here the inhibitor binds to a separate site away from the substrate binding site causing disturbance in the latter site. This causes permanent disturbance in the enzyme leading to non binding of the substrate.  With the above brief discussion regarding enzyme inhibitors let us now deal with enzyme inhibitors obtained from microorganisms which find the use in many ailments like cancers, ulcers, etc. Three decades back i.e., around 1974, 50 microbial enzyme inhibitors were known. Initially, the study was conducted on Protease Inhibitors which by themselves are peptides but were modified to find use as antitumors and immunosuppressive.In this context, refer the attachment microbes.jpg In the year 1970's, screening for inhibitors of enzyme HMGCoA was carried out. Structurally related compounds compactin and mevinolin were discovered from fungal culture broths as potent and specific inhibitors of the enzyme HMGCoA reductase. As we know Statins are the most popularly used drugs for treating hypercholesterolemia and have a huge market share globally. With the above discovery, the derivatives lovastatin and provastatin have been included in the statins. Now, novel synthetic inhibitors of the enzyme such as Cerivastatin are noted as better agents. Omura and Co-workers have done a great research in isolation and screening of enzyme inhibitors of microbial origin. Here are few discovered by the scientists. In this context, refer the attachment omura.jpg THIS BLOG DOES NOT CONTAIN PLAGIARIZED MATERIAL Ref: 1. http://www.lsbu.ac.uk/biology/enztech/inhibition.html accessed on 10th March 2011. 2. Biotechnology - A Text Book of Industrial Microbiology by Wulf Crueger and Anneliese Crueger, Second edition, Panima Publishing Corporation, New Delhi/Bangalore,Page no 337-338 3. Enzyme Technologies for Pharmaceutical and Biotechnological Applications- Edited by Herbert A. Kirst, Wu-Kuang Yeh, Milton J Zmijewski, Jr. Published by Marcel Dekker Inc. NY. Page no : 343-344.