Directed evolution method

Directed evolution methods, as well as rational structure-based mutagenesis approaches, have been successful in broadening the substrate tolerance of aldolases. A common goal is to... 

Enchira Biotechnology, EBC, which was headquartered near Houston, TX, used to be the largest biotechnological platform devoted to the development of biorefining processes. EBC acquired Energy Biosystems in June 2000 and continued the R D activities on BDS during the last years. This company applied directed evolution methods to accelerate development and commercialization of gene-based products for the industrial... 

Recently, Turner et al. described the synthesis of the alkaloid (R)-(-t-)-crispine A, which shows cytotoxic activity against HeLa human cancer cell lines, using in the final step a deracemization procedure with the combination of an enantioselective amine oxidase obtained by directed evolution methods and a chemical non-selective reducing agent (Scheme 10.20) [48]. 

Figu re 10.20 Production of (+)-crispine A using an amino oxidase obtained by directed evolution methods. 

As a result of the broad use of hydantoinases for the preparation of both proteogenic and nonproteogenic amino acids, studies into their structure and mechanism continue to be pursued.414-416 Directed evolution methods have been used to invert the enantioselectivity of an hydantoinase for the production of L-methionine,417 and improvement in catalytic efficiency of an hydantoinase through mutagenesis has been reported.418... 

Meanwhile, directed evolution methods that combine mutagenesis of genes with high-throughput screening of functional gene products have developed rapidly. 

Inverting Stereochemistry. Altering the stereochemical outcome of an enzyme reaction in order to access both stereoisomers is more challenging, because the main scaffold of the protein, which is invariably cmistructed from L-amino acids, remains the same. Nevertheless, successful examples were reported using rational [523-527] or directed evolution methods [528, 529],... 

One of the most promising approaches for elucidation of enzyme catalytic mechanisms and designing new catalysts is a directed evolution , method of purposeful mutation of non-enzymatic proteins to evolve desired activity mimicking native enzymes. Another important trend in chemical and oizyme catalysis is the growing role of theoretical calculation of thermo mamic parameters of enzyme reactions, conqniter analysis of X-ray structural models, taking from Data Base, computer modeling of structure of chemical catalysts and enzymes and their interaction with substrates and inhibitors, and theoretical construction of transition and pretransitim states of reactions of interest. 

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