We report the development of a tandem chemoenzymatic transformation that combines alkene metathesis with enzymatic epoxidation to provide aryl epoxides. The development of this one-pot reaction required substantial protein and reaction engineering to improve both selectivity and catalytic activity. Ultimately, this reaction converts a mixture of alkenes into a single epoxide product in high ena...

A physical model is described for the simultaneous enzymatic bioconversion of a nonelectrolyte solute and the passive transport of both the solute and product of the enzymatic reaction out of cells in culture suspension. The plasma membrane is assumed to be the rate-determining transport barrier. This model provides the basis for the experimental design and analysis of the Michaelis-Menten kine...

One of the most intriguing questions in modern enzymology is whether enzyme dynamics evolved to enhance the catalyzed chemical transformation. In this study, dihydrofolate reductase, a small monomeric protein that catalyzes a single C-H-C transfer, is used as a model system to address this question. Experimental and computational studies have proposed a dynamic network that includes two residue...

A ratiometric fluorescent system for CaE detection with AIE dots as the FRET donors was designed. Upon enzymatic reaction, electrostatic interaction between the cationic TPE-N(+) dots and the enzymatic reaction product - the negatively charged fluorescein molecules - allows the FRET process to proceed, thus affording the ratiometric fluorescence CaE assay.

organophosphorus compounds are highly toxic chemicals that have application in production of warfare agents and agricultural pesticides. detoxification of areas that have been exposed to these types of materials is of vital importance and several approaches have been used for this purpose. biodegradation of organophosphates is one of these approaches that is in the center of attention due to it...

A mathematical model of biosensors acting in a trigger mode has been developed. One type of the biosensors utilized a trigger enzymatic reaction followed by the cyclic enzymatic and electrochemical conversion of the product (CCE scheme). Other biosensors used the enzymatic trigger reaction followed by the electrochemical and enzymatic product cyclic conversion (CEC scheme). The models were base...

Corn bran is a by-product from corn starch processing. This work examined the effects of changing substrate particle size on enzymatic hydrolysis of both raw and pretreated destarched corn bran. The biomass composition of the corn bran varied between particle size fractions: The largest particles ([1000;710]μm) were richer in cellulose and in (arabino) xylan with a relatively low degree of arab...

A stopped-flow clinical analyzer is described that makes use of a reaction loop containing immobilized enzyme(s) for the determination of the analyte/substrate. The analyzer has been evaluated by determining glucose with immobilized glucose oxidase. The stopped-flow mixing system was constructed at a current cost of less than $500. The analyzer separates the enzymatic reaction from a followup,...

Enzymes are remarkable catalysts that lie at the heart of biology, accelerating chemical reactions to an astounding extent with extraordinary specificity. Enormous progress in understanding the chemical basis of enzymatic transformations and the basic mechanisms underlying rate enhancements over the past decades is apparent. Nevertheless, it has been difficult to achieve a quantitative understa...