The relative contribution of acylglycerols and phospholipids to the lipid hydrolysis on milled rice was investigated during storage at 37°C and 70% relative humidity for 50 days. The monoglycerol, diglycerol, and lysophospholipid contents of surface lipid were determined by reversed-phase HPLC. Monoand diglycerol content of milled rice increased during storage from 0.06% to 0.18% (w/w milled ri...

An antibody generated against a neutral phosphonate diester transition-state (TS not equal to) analog catalyzes the formation of an amide bond between a phenylalanyl amino group and an acyl azide derived from L-alanine. The antibody is selective for L- vs. D-alanine and does not catalyze the hydrolysis of the acyl azide to an appreciable degree. A rate acceleration of 10,000-fold relative to th...

Liposomes were incubated with an extract of human plantar stratum corneum. The liposomal lipids were hydrolysed, if composed of soy-bean phosphatidylcholine or phosphatidylglycerol. Rigid lipids were not degraded. The temperature optimum of the hydrolysis was between 30-35degC. CaCl enhanced, while EDTA reduced the rate of hydrolysis, indicating that the hydrolysis is due to a phospholipase A(2).

Liposomes were incubated with an extract of human plantar stratum corneum. The liposomal lipids were hydrolysed, if composed of soy-bean phosphatidylcholine or phosphatidylglycerol. Rigid lipids were not degraded. The temperature optimum of the hydrolysis was between 30-35°C. CaCl2 enhanced, while EDTA reduced the rate of hydrolysis, indicating that the hydrolysis is due to a phospholipase A2.

methylene blue is widely used in various industrial branches. due to insufficient treatment, its occurrence in wastewater is frequently detected, which may result in serious environment problems to aquatic organisms. hydroponic experiments were conducted with rice seedlings (oryza sativa l. cv. xzx 45) exposed to methylene blue to determine the effective concentration using relative growth rate...

The concentration of acetylcholine (ACh) in the synaptic cleft at the neuromuscular junction (NMJ) remains impossible to quantify using direct measurements based upon spatio-temporal resolution. We present a model of the concentration of ACh in the synaptic cleft. Our model considers the release mechanism and the clearance process, represented by the hydrolysis of acetylcholinesterase (AChE) an...

1. The rate of hydrolysis at different pH values of glycyl glycine, glycyl leucine, glycyl alanine, glycyl asparagine, glycyl aspartic acid and biuret base has been determined. 2. The pH-activity curves obtained in this way differ for the different substrates. 3. The curves can be satisfactorily predicted by the assumption that erepsin is a weak acid or base with a dissociation constant of 10(-...

The bacterial phosphotriesterase from Pseudomonas diminuta is a zinc metalloenzyme which catalyzes the hydrolysis of a variety of organophosphorus nerve agents with high efficiency. The active site of the enzyme consists of a coupled binuclear metal center embedded within a cluster of histidine residues. Potential protein-substrate interactions at the active site were probed by a systematic var...