The polymerization of actin has been studied with applying a new method of microcalorimetric measurement in vitro. The thermodynamic parameters of actin poly merization at 310.15K is reported. △Hm= 49.26kJ·mol-1...The polymerization of actin has been studied with applying a new method of microcalorimetric measurement in vitro. The thermodynamic parameters of actin poly merization at 310.15K is reported. △Hm= 49.26kJ·mol-1， △G=-25.62kJ·mol-1 and △S=241 .54J·K-1×mol-1. Thermogram showed that the thermokinetic process of actin polymerization had two different thermal effects where in the first exothermic step is con sidered to be the total results of several reations: metal ion (Mg2+, K+) binding to actin;the change of conformation of actin and hydrolysis of ATP in actin; and the second en dothermic step is assigned to the results of association and length adjustment (annealing process). Cisplatin, at lower concentration, affects the polymerization of G-actin reflected in the decrease of △Hm; and at higher concentration it induces the crosslinking and de polymerization of F-actin in the equilibrium system of G/F. The experimental results manifest that when the concentration of cisplatin is increased to a certain value, the sign of △Hm will be changed from positive to negative i. e. the magnitude and sign of △Hm of actin polymerization is dependent on the concentration of cisplatin. This is possibly related to the pharmacologic or toxicological action of cisplatin.展开更多
The thermal power time relation of starch hydrolysis reaction catalyzed by hydrolytic enzyme has been evaluated using a microcalorimeter . The maximum velocity( V max ) was calculated according to the equation V max =...The thermal power time relation of starch hydrolysis reaction catalyzed by hydrolytic enzyme has been evaluated using a microcalorimeter . The maximum velocity( V max ) was calculated according to the equation V max =[-2 975 79×10 -4 +2 401 91×10 -4 pH-6 940 00×10 -5 pH 2+ 9 040 00× 10 -6 pH 3-4 450 00×10 -7 pH 4] g/(dm 3·s) .The optimum acidity was found to be pH=5 78.展开更多
Bacterial growth thermograms of fungistatic action using a thermal activity monitor have been determined. The growth rate constants at different concentration drugs and the critical growth concentrations of the drug h...Bacterial growth thermograms of fungistatic action using a thermal activity monitor have been determined. The growth rate constants at different concentration drugs and the critical growth concentrations of the drug have also been calculated.展开更多
The power time curves of the extraction oscillation reaction were determined at different temperatures for the extraction of hydrochloric acid and phosphoric acid by primary amine N1923 in chloroform, using a titratio...The power time curves of the extraction oscillation reaction were determined at different temperatures for the extraction of hydrochloric acid and phosphoric acid by primary amine N1923 in chloroform, using a titration microcalorimetric method. The apparent activation energy were calculated from the induction period( t in ), the first oscillation period( t p.1 ) and the second oscillation period( t p.2 ). The oscillation behavior were discussed.展开更多
文摘The polymerization of actin has been studied with applying a new method of microcalorimetric measurement in vitro. The thermodynamic parameters of actin poly merization at 310.15K is reported. △Hm= 49.26kJ·mol-1， △G=-25.62kJ·mol-1 and △S=241 .54J·K-1×mol-1. Thermogram showed that the thermokinetic process of actin polymerization had two different thermal effects where in the first exothermic step is con sidered to be the total results of several reations: metal ion (Mg2+, K+) binding to actin;the change of conformation of actin and hydrolysis of ATP in actin; and the second en dothermic step is assigned to the results of association and length adjustment (annealing process). Cisplatin, at lower concentration, affects the polymerization of G-actin reflected in the decrease of △Hm; and at higher concentration it induces the crosslinking and de polymerization of F-actin in the equilibrium system of G/F. The experimental results manifest that when the concentration of cisplatin is increased to a certain value, the sign of △Hm will be changed from positive to negative i. e. the magnitude and sign of △Hm of actin polymerization is dependent on the concentration of cisplatin. This is possibly related to the pharmacologic or toxicological action of cisplatin.
文摘The thermal power time relation of starch hydrolysis reaction catalyzed by hydrolytic enzyme has been evaluated using a microcalorimeter . The maximum velocity( V max ) was calculated according to the equation V max =[-2 975 79×10 -4 +2 401 91×10 -4 pH-6 940 00×10 -5 pH 2+ 9 040 00× 10 -6 pH 3-4 450 00×10 -7 pH 4] g/(dm 3·s) .The optimum acidity was found to be pH=5 78.
文摘Bacterial growth thermograms of fungistatic action using a thermal activity monitor have been determined. The growth rate constants at different concentration drugs and the critical growth concentrations of the drug have also been calculated.
文摘The power time curves of the extraction oscillation reaction were determined at different temperatures for the extraction of hydrochloric acid and phosphoric acid by primary amine N1923 in chloroform, using a titration microcalorimetric method. The apparent activation energy were calculated from the induction period( t in ), the first oscillation period( t p.1 ) and the second oscillation period( t p.2 ). The oscillation behavior were discussed.
