I describe an enzymatic method for determing serum triglycerides (triacylglycerols). The triglycerides are hydrolyzed by a mixture of lipase and esterase. The glycerol released is determined by kinetic fixed-time analysis, with use of glycerol kinase, pyruvate kinase, and lactate dehydrogenase. Through addition of the competitive inhibitor ATP the Michaelis constant of pyruvate kinase is appare...

ENZYMATIC REACTIONS, BECAUSE of their great specificity, are among the most valuable analytic tools at the disposal of the chemist. The method for glucose here described represents an adaptation of such biologic reagents and is a distinct departure from sugar methods now in common use. It is based upon a unique principle communicated to us by Keston (1) prior to publication (2). Traditional met...

X X Ž X . The phosphorylation of inosine in the 5 -position to produce inosine-5 -monophosphate 5 -IMP was studied in a number Ž . of microorganisms from our culture collection using pyrophosphate PPi as the phosphate source. Although many of the microorganisms screened were able to phosphorylate inosine, phosphotransferase activity specific to the 5-position was found to be distributed among t...

nineteen bread wheat genotypes were selected to examine the effect of glycine betaine (gb, 100 mm) on various photosynthetic gas exchange parameters under drought stress and to study the relationship of these parameters with non-enzymatic antioxidants. drought stress caused a significant decline in net co2 assimilation rate (pn), stomatal conductance (gs), intercellular co2 concentration (ci) a...

for the first time in the present study the effects of vanillin, vanillyl alcohol, vanillic acid, as well as the newly synthesized vanillin derivative, bis-vanillin, were investigated on the oxidation of dopamine hydrochloride by mushroom tyrosinase. among them, vanillin and bis-vanillin act as activators, while vanillyl alcohol and vanillic acid exhibited inhibitory effects, the ic50 values be...

introduction: α-amylase is a major form of amylase found in humans and other mammals. it is the special key enzyme involved in carbohydrates breakdown. inhibition of this enzyme could be used in treatment of diabetes. in this study, the effect of ten iranian macrolichens on alpha amylase were tested. methods: different concentrations of the extracts (25, 50 and 75 mg/ml) were incubated with enz...

An enzymatic rate assay is described for measuring cholesterol in serum. Cholesterol is analyzed by mixing 5 mul of sample with a reagent consisting of cholesterol esterase, cholesterol oxidase, catalase, acetylacetone, methanol, and hydroxypolyethoxydodecane in a ammonium phosphate buffer at pH 7.0. The rate of increase in absorbance of the dihydrolutidine product is measured at 37 degrees C ...

A crude cell extract from a mixed bacterial culture growing on parathion, an organophosphate insecticide, hydrolyzed parathion (21 C) at a rate of 416 nmol/min per mg of protein. This rate of enzymatic hydrolysis, when compared with chemical hydrolysis by 0.1 N sodium hydroxide at 40 C, was 2, 450 times faster. Eight of 12 commonly used organophosphate insecticides were enzymatically hydrolyzed...