Radical clock substrate probes were used to assess the viability of a discrete substrate radical species in the mechanism of hydrocarbon oxidation by the soluble methane monooxygenase (sMMO) from Methylococcus capsulatus (Bath). New substituted cyclopropane probes were used with very fast ring-opening rate constants and other desirable attributes, such as the ability to discriminate between rad...

Rat hepatic phenylalanine hydroxylase requires both a tetrahydropterin cofactor and molecular oxygen to convert phenylalanine to tyrosine. During the physiological hydroxylation, a single mol of the natural cofactor, tetrahydrobiopterin, is oxidized for each mol of phenylalanine converted to tyrosine. Artificial conditions have been devised in which the oxidation of the tetrahydropterin is unco...

Recent human and animal studies have demonstrated that in severe end-stage heart failure (HF), the cardiac muscle switches to a more fetal metabolic phenotype, characterized by downregulation of free fatty acid (FFA) oxidation and an enhancement of glucose oxidation. The goal of this study was to examine myocardial substrate metabolism in a model of moderate coronary microembolization-induced H...

The effect of epinephrine and glucagon on W02 production from C-l-labeled branched chain amino acids, [I-W]pyruvate, [1-Wlalanine, and [U-14Clglucose, was studied in isolated diaphragms and petiused hearts. The tissues were obtained from rats fed ad libitum or fasted for 48 hours. Epinephrine (10m4 M) stimulated *4CO~ production from Ieuciue, valine, and alanine by hemidiaphragms of fasted rats...

We have examined the ion transport properties and the inhibition of rat liver mitochondrial substrate oxidation by the antibiotic W341C. W341C was able to transport 22Na+ and 42K+ across a bulk carbon tetrachloride layer. A preference was shown for K+ transport. With equal molar antibiotic concentrations, W341C transported 42K+ at a greater rate than the K+-selective ionophore nigericin, but tr...

An in situ coupled oxidation cycle that allows catalytic oxidation of a substrate with catalytic amounts of o-chloranil and novel reusable polymer-immobilized platinum nanocluster catalysts using molecular oxygen as the terminal oxidant was developed.

Co-oxidation is a little understood means of microbial degradation of petroleum hydrocarbons. In co-oxidation, microbes growing on one compound, the growth substrate, are able to oxidize a second · compound, the cosubstrate. This project examines the role of co-oxidation in the degradation of polycyclic aromatic hydrocarbons (PAR's), one of the most recalcitrant petroleum compounds now found in...

How an enzyme activates its substrate for turnover is fundamental for catalysis but incompletely understood on a structural level. With redox enzymes one typically analyses structures of enzyme–substrate complexes in the unreactive oxidation state of the cofactor, assuming that the interaction between enzyme and substrate is independent of the cofactors oxidation state. Here, we investigate the...

AIMS Development of heart failure is known to be associated with changes in energy substrate metabolism. Information on the changes in energy substrate metabolism that occur in heart failure is limited and results vary depending on the methods employed. Our aim is to characterize the changes in energy substrate metabolism associated with pressure overload and ischaemia-reperfusion (I/R) injury....

We explored the coupling of laccases to magnetic nanoparticles (MNPs) with different surface chemical coating. Two laccase variants offering two opposite and precise orientations substrate oxidation site were immobilised onto core-shell MNPs presenting either aliphatic aldehyde, aromatic aldehyde or azide functional groups at particles surface. Oxidation capabilities six-resulting laccase-MNP h...