An efficient and sensitive analytical method based on high-performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD) was established for the simultaneous separation and determination of glucosamine (GlcN)₁ and chitooligosaccharides (COS) ranging from (GlcN)₂ to (GlcN)₆ without prior derivatization. Detection limits were 0.003 to 0.016 mg/L (corresponding to 0.4-0....

The conditions for optimal rates of ATP hydrolysis catalyzed by the chloroplast ATP-synthase (A TPase), CFoF,, after isolation and reconstitution into asolectin liposomes have been investi­ gated. The rate of ATP hydrolysis was measured either after oxidation of CF0F, (by incubation with iodosobenzoate) or after reduction of CFoF, (by incubation with dithiothreitol). In both cases a rate of abo...

BACKGROUND The availability and low cost of lignocellulosic biomass has caused tremendous interest in the bioconversion of this feedstock into liquid fuels. One measure of the economic viability of the bioconversion process is the ease with which a particular feedstock is hydrolyzed and fermented. Because monitoring the analytes in hydrolysis and fermentation experiments is time consuming, the ...

A number of the components of the tissues contain in their molecules either phosphoric or sulfuric acid. The phosphoric acid radicle is contained in the monoand polynucleotides, and the sulfuric acid radicle in chondroitinand mucoitin-sulfuric acids. In all these compounds the acid radicle is linked in ester form to either a carbohydrate or a polyhydric alcohol. On long acquaintance with substa...

The biodegradation and hydrolysis rates of an aliphatic aromatic copolyester were measured in manure, food, and yard compost environments and in phosphate buffer solution (pH 1⁄4 8.0) and vermiculite at 58 C. Mineralization, molecular weight reduction, and structural changes determined by DSC, FTIR, and 1H NMR were used as indicators of the biodegradation and hydrolysis rates. Poly(butylene adi...

The esterase-like activity of human serum albumin (HSA) toward esters of nicotinic acid was investigated under a variety of conditions such as protein concentration, temperature, pH, ionic strength, nature of buffers, and presence of organic solvents. Initial rate constants of hydrolysis of 18 nicotinates in the presence of 50 microM HSA were measured at pH 7.4 and 37 degrees C. The substrates ...

Alkaline phosphatase from Escherichia coli catalyzes the hydrolysis of S-substituted monoesters of phosphorothioic acid of the type RSP03Naz (R = -CH2CH2NH2,-CH2CHzNHCOCH3,-CH,COOH, or -CH2CHzCOOCzH~), at the S-P bond, to yield orthophosphate and the corresponding thioalcohols. The rate of enzymic hydrolysis of cysteamine S-phosphate was measured at different pH values and substrate concentrati...

When concentrated dispersions of tripalmitin in Triton X-100 are added to reaction mixtures containing soluble beef liver lipase, the rate of hydrolysis of tripalmitin increases with incubation time. When the diluted substrate is aged at 37 degrees C for 3 hr before the addition of enzyme, the rate of hydrolysis is greater than the rate with freshly diluted dispersions and is constant for at le...