Sucralose, one of the popular non-caloric artificial sweeteners, has been known to influence enzymatic conversion sucrose glucose and fructose by invertase. In continuing use real-time NMR experiments reaction progress curve analysis measure enzyme kinetics, here we investigate role sucralose as an inhibitor. based kinetic were performed a function substrate concentration for range concentratio...

A key step towards a chemical picture of enzyme catalysis was taken in 1913, when Leonor Michaelis and Maud Menten published their studies of sucrose hydrolysis by invertase. Based on a novel experimental design and a mathematical model, their work offered a quantitative view of biochemical kinetics well before the protein nature of enzymes was established and complexes with substrates could be...

The enzyme kinetics of estrogen 2-hydroxylase from rat liver microsomes has been investigated using two radiotracer methods. The conversion of [4-14C]estradiol to [4-14C]2-hydroxyestradiol by microsomes was examined by isolation of the catechol estrogen. [6,7-3H]2-Hydroxyestradiol was prepared and added at the end of the incubation as a recovery marker for quantitation. Initial velocity conditi...

The metabolism of a number of compounds by the cytochrome P-450 subfamily CYP3A does not exhibit classic Michaelis-Menten kinetics but displays a sigmoidal rate-substrate concentration relationship. Intrinsic clearance (CLint) cannot be calculated for these drugs due to the lack of a first order region in their kinetic profiles, and a suitable parameter has yet to be identified to allow such da...

To understand the behaviour of complex systems, it is often necessary to use models that describe the dynamics of subnetworks. It has previously been established using projection methods that such subnetwork dynamics generically involves memory of the past and that the memory functions can be calculated explicitly for biochemical reaction networks made up of unary and binary reactions. However,...

We develop quantitative optimization criteria for transient digestion processes in simple animal tracts that can be modeled by a semi-batch reactor or plug flow reactor. Specifically, we determine the residence time that optimizes the average net energy intake over the total residence time. The net energy is measured by the total energy intake, less the cost of foraging and digestion. Precise v...

A number of proteins can aggregate into amyloid-like fibrils. It was noted that fibril elongation has similarities to an enzymatic reaction, where monomers or oligomers would play a role of substrate and nuclei/fibrils would play a role of enzyme. The question is how similar these processes really are. We obtained experimental data on insulin amyloid-like fibril elongation at the conditions whe...

A comparison is made between conventional Michaelis-Menten kinetics and two models that take into account the duration of the conformational changes that take place at the molecular level during the catalytic cycle of a monomer. The models consider the time that elapses from the moment an enzyme-substrate complex forms until the moment a product molecule is released, as well as the recovery tim...

In batch cultures of four Mediterranean strains (from France, Italy, and Spain) of Alexandrium catenella (Whedon et Kof.) Balech growing on a daily light cycle, ammonium and urea uptake were estimated by the (15) N tracer technique. Ammonium uptake could be described by Michaelis-Menten kinetics along a substrate gradient of 0.1-10 μgat N · L(-1) for the four strains, while two different patter...