To estimate the proficiency of inorganic pyrophosphatase as a catalyst, (31)P NMR was used to determine rate constants and thermodynamics of activation for the spontaneous hydrolysis of inorganic pyrophosphate (PP(i)) in the presence and absence of Mg(2+) at elevated temperatures. These values were compared with rate constants and activation parameters determined for the reaction catalyzed by E...

Hydrolysis is the most critical stage in high solids Temperature Phased Anaerobic Digestion (TPAD). In this paper two different Organic Fraction of Municipal Solid Waste (OFMSW) types were tested co-digestion with Digested Sludge (DS) at temperatures: 37, 55 and 65 °C. Volatile fatty acids (VFAs), soluble chemical oxygen demand (CODs) Biochemical Methane Production (BMP) measured calculated aft...

The RecA and some related proteins possess a simple motif, called (KR)X(KR), that (in RecA) consists of two lysine residues at positions 248 and 250 at the subunit-subunit interface. This study and previous work implicate this RecA motif in the following: (a) catalyzing ATP hydrolysis in trans,(b) coordinating the ATP hydrolytic cycles of adjacent subunits, (c) governing the rate of ATP hydroly...

The potential for using readily available and cost-effective complex carbon sources such as primary sewage sludge for a range of biological processes, including the bioremediation of acid mine drainage, has been constrained by the slow rate of solubilisation and low yield of soluble products, which drive the above mentioned processes. Previous research into the hydrolysis of complex organic mat...

Acid-catalyzed hydrolysis of the methox-ytropone moiety of colchicine has been shown to proceed at a greater rate than in the case of isocolchicine1. (Struc­ tures are shown in Table I.) No interpretation of this rate difference has been offered. And, while a mecha­ nism for the acid-catalyzed hydrolysis of 2 -methoxytropone has been proposed2, no kinetic data on this type of reaction either fo...

Neutrase 0.8L and N120P proteases were used for oligopeptide production from apricot almonds meal, and response surface design was carried out to optimize the effect of hydrolysis conditions on hydrolysis degree (DH) and oligopeptide yield rate. Four independent variables were used to optimize the hydrolysis process: hydrolysis temperature (X(1)), enzyme-to substrate ratio (E/S) (X(2)), substra...

The kinetics of binding and hydrolysis of ATP by bovine cardiac myosin subfragment 1 has been reinvestigated. More than 90% of the total fluorescence amplitude associated with ATP hydrolysis occurs with an apparent second-order rate constant of 8.1 X 10(5) M-1 S-1 and a limiting rate constant of approximately 140 S-1 (100 mM KCl, 50 mM 1,3-bis-[tris(hydroxymethyl)methylamino]-propane, 10 mM MgC...

The kinetics of ATP hydrolysis and tension responses were studied simultaneously in a permeabilized preparation of cardiac tissue of the guinea pig. This was achieved by combining laserflash photolysis of P3-1-(2-nitrophenyl)ethyladenosine 5'-triphosphate ("caged-ATP") and a rapid freezing technique. In the presence of calcium ions, tension increased following the photolytic production of ATP w...

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...