Proteins catalystic power

Nobel-laureate Richard Feynman once said that the principles of physics do not preclude the possibility of maneuvering things atom by atom (260). Recent developments in the fields of physics, chemistry, and biology (briefly described in the previous sections) bear those words out. The invention and development of scanning probe microscopy has enabled the isolation and manipulation of individual atoms and molecules. Research in protein and nucleic acid stmcture have given rise to powerful tools in the estabUshment of rational synthetic protocols for the production of new medicinal dmgs, sensing elements, catalysts, and electronic materials. 

Enzymes are proteins catalyzing all in vivo biological reactions. Enzymatic catalysis can also be utilized for in vitro reactions of not only natural substrates but some unnatural ones. Typical characteristics of enzyme catalysis are high catalytic activity, large rate acceleration of reactions under mild reaction conditions, high selectivities of substrates and reaction modes, and no formation of byproducts, in comparison with those of chemical catalysts. In the field of organic synthetic chemistry, enzymes have been powerful catalysts for stereo- and regioselective reactions to produce useful intermediates and end-products such as medicines and liquid crystals. ... 

The catalysts are enzymes, most of which are proteins. Not only are they catalysts, bnt their catalytic powers are enormous they can increase the rate of a reaction by several orders of magnitnde. Indeed, in the absence of enzymes, life as we know it wonld not be possible. One remarkable example of the nse of the catalytic power of two enzymes in biology is the Bombardier beetle it uses the enormous catalytic power of the enzymes catalase and a peroxidase to deter predators (Box 3.1). 

In this chapter, then, we turn our attention to the reaction catalysts of biological systems the enzymes, the most remarkable and highly specialized proteins. Enzymes have extraordinary catalytic power, often far greater than that of synthetic or inorganic catalysts. They have a high degree of specificity for their substrates, they accelerate chemical reactions tremendously, and they function in aqueous solutions under very mild conditions of temperature and pH. Few non-biological catalysts have all these properties. 

The active biochemical constituents of cells are a particular group of proteins which have catalytic properties. These catalytic proteins, or enzymes, are in some ways similar to inorganic catalysts but are distinctive in other, quite important respects. Enzymes are very powerful catalysts, capable of enhancing the overall rates of reactions much more markedly they are much more specific than the average inorganic catalyst. 

Proteins are polymers produced from amino acids that are joined by peptide linkages (amine-group carboxylic acid bonds). These compounds form the bulk of living tissue. Enzymes, those very selective and powerful catalysts, are also proteins. Enzymes may contain a group based on a metal atom, as may molecules from other classes of compounds (hemoglobin, chlorophyll, etc.). Some proteins serve special functions, such as hemoglobin, an oxygen carrier. 

The third research project presented by Rohlfing looked at the intrinsic motions of proteins as they influence catalysis and enzymes. Characterizing the intrinsic motions of enzymes is necessary to fully understand how they work as catalysts. As powerful as structure-function relationships are, the motion of these proteins is intimately connected with their catalytic activity and cannot be viewed as static structures. This realization, asserted Rohlfing, could revolutionize and accelerate approaches to biocatalyst design or directed evolution, and could alter understanding of the relations between protein structure and catalytic function. 

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