The concurrent effects of two enzyme inhibitors have been analysed previously with the Yonetani-Theorell plot to obtain insight into the interactions between bound inhibitors. This procedure, like many other traditional graphical methods in enzymology, is based on the estimation of intersecting tendencies in a family of lines. In a recent paper from this laboratory [Chan (1995) Biochem. J. 311,...

The halogenases are a group of enzymes that have only come to the fore over the last 10 years thanks to the discovery and characterization of several novel representatives. They have revealed the fascinating variety of distinct chemical mechanisms that nature utilizes to activate halogens and introduce them into organic substrates. Computational studies using a range of approaches have already ...

Now, more than ever, enzymology and its development can be considered of vital importance to the progression of the biological sciences. With an increase in the numbers of enzymes being identified from genomic studies, enzymology is key to defining the structural and functional properties of these enzymes in order to establish their mechanisms of action and how they fit into metabolic networks....

there have been numerous efforts to formulate insulin into an oral dosage form. the major problems involved with the oral administration of insulin are acidic and enzymatic decomposition by the gastric medium, and poor absorption in the small intestine due to its macromolecular structure. this study attempted to test the enhancing ability of two absorption enhancers, sodium glycocholate (na-gc)...

Signaling in enzymatic networks is typically triggered by environmental fluctuations, resulting in a series of stochastic chemical reactions, leading to corruption of the signal by noise. For example, information flow is initiated by binding of extracellular ligands to receptors, which is transmitted through a cascade involving kinase-phosphatase stochastic chemical reactions. For a class of su...

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...

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...