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...

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...

in this study the bacterial growth inhibitory activity of peptide fragments produced from goat’s milk whey proteins by enzymatic hydrolysis using trypsin, ficin and a combination of both was investigated. goat’s milk whey proteins were isolated and subjected to enzymatic hydrolysis and peptides were purified by ultrafiltration followed by reverse-phase high-performance liquid chromatography (rp...

in present study, it was determinated lc50 96-h and toxicity degree of diazinon in huso huso, then were evaluated effects of sub-lethal concentrations on tow general enzymatic indices including alanine and aspartate aminotransferase of plasma and one specific enzymatic index including tissue ache enzyme. the median lethal concentration, lowest observed effect concentration and maximum allowable...

The effectiveness of pineapple juice in enzymatic browning inhibition was evaluated on the cut surface of banana slices. After storage of banana slices at 15 degrees C for 3 days, pineapple juice showed browning inhibition to a similar extent as 8 mM ascorbic acid but less than 4 mM sodium metabisulfite. Fractionation of pineapple juice by a solid-phase C18 cartridge revealed that the directly ...

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...

Life as we know it heavily relies on biological catalysis, in fact, in a very nonromantic version of it, life could be considered as a series of chemical reactions, regulated by the guarding principles of thermodynamics. In ancient times, a beating heart was a good sign of vitality, however, to me, it is actually the presence of active enzymes that counts… Though we do not usually pay attention...