The reaction between Laccase and o methoxyphenol have been studied by LKB 2107 batch microcalorimetry system. Thermodynamic parameters Δ rH m , Δ G 0 , Δ G ≠ T ,) and kinetic parameters ( K m,k...The reaction between Laccase and o methoxyphenol have been studied by LKB 2107 batch microcalorimetry system. Thermodynamic parameters Δ rH m , Δ G 0 , Δ G ≠ T ,) and kinetic parameters ( K m,k 2 ) have been determined. The process of the reaction has been analyzed from changes in energy by using the transition state theory. Two methods for enhancing catalytic power of Laccase are proposed. The results shown that formation of an enzyme substrate complex is“anticatalytic”. The enter and sole source of catalytic power is the stabilization of transition state; reactant state interactions are by nature inhibitory and only waste catalytic power.展开更多
The molar reation enthalpy,the Michaelis constant and the observed rate constant of the reaction between the Rhus vernicifera laccase and p-phenylenediamine have been determined at 298. 15 K by LKB-2107 microcalorimet...The molar reation enthalpy,the Michaelis constant and the observed rate constant of the reaction between the Rhus vernicifera laccase and p-phenylenediamine have been determined at 298. 15 K by LKB-2107 microcalorimetry system in 0.1 mol/L phosphate salt buffer (pH7. 4) to be △rHm=-136.36±0. 36kJ/mol, Km= 5. 58×10-3 mol/L and k1 =8. 63×10-3s-1, respectively. The catalyst activity of laccase withp-phenylenediamine as substrate has been determined to be EA=0. 045 IU in the experimental condition.The observed activation energy of non-enzymic step of the reaction, the Gibbs binding energy of the combination process of laccase and substrate have been also calculated. The physical significance of the determined parameters were discussed for different step of the reaction.展开更多
The thermokinetic reduced extent equations of reversible inhibitions for Michaiels-Menten enzymatic reaction were deduced, and then the criteria for distingushing inhibition type was given and the methods for calculat...The thermokinetic reduced extent equations of reversible inhibitions for Michaiels-Menten enzymatic reaction were deduced, and then the criteria for distingushing inhibition type was given and the methods for calculating kinetic parameters, KM,Ki and Urn were suggested. This theory was applied to inverstigate the inhibited thermokinetics of laccase-catalyzed oxidation of o-dihydroxybenzene by m-dihydroxybenzene. The experimental results show the inhibition belongs to reversible competitive type, KM=6.224×10-3 mol L-1, Ki=2. 363 × 10-2 mol. L-1.展开更多
Microcalorimetric bioassay for acute cellular toxicity is based on metabolicheat production from cultured cells. The biological response to toxicants is the inhibition of theheat production rate in cells, and toxicity...Microcalorimetric bioassay for acute cellular toxicity is based on metabolicheat production from cultured cells. The biological response to toxicants is the inhibition of theheat production rate in cells, and toxicity is expressed as the concentration of toxicant that is50% effective to this inhibition (IC_(50)). In this paper, the effect of Na_2SeO_3 on Bacillussubtilis growth was investigated at 37℃ by microcalorimetry. The relationship between growth rateconstants (k) and concentration of Na_2SeO_3(c) shows a logarithmic normal distribution, and IC_(50)is 20.3 μg/mL. All these thermokinetic information is readily obtained by an LKB 2277-204 heatconduction microcalorimeter. Microcalorimetry is a quantitative, inexpensive, and versatile methodfor toxicology research.展开更多
With or without activation or inhibition of metal ion,the power-time curves of amylase catalyzed reaction were determined by a 2277 thermal activity monitor (Sweden). The Michaelis constant ( K ),apparent Michaelis co...With or without activation or inhibition of metal ion,the power-time curves of amylase catalyzed reaction were determined by a 2277 thermal activity monitor (Sweden). The Michaelis constant ( K ),apparent Michaelis constant ( K _m),maximum velocity ( v _m) and apparent maximum velocity ( v _ am ) of amylase catalyzed reaction were obtained using thermokinetic theory and reduced extent method. On the basis of data obtained,the following relationships between K _m and concentration of metal ion ( c ) were established: for inhibitor of Ni 2+ K _m=2.9648×10 -3 -1.3912×10 -4 cR =0.9998for inhibitor of Co 2+ K _m=1.0227×10 -3 +8.2676×10 -6 cR =0.9955for activator of Ca 2+ K _m=1.0630×10 -7 c 2-1.8311×10 -6 c +9.3058×10 -6 R =0.9999for activator of Li + K _m=5.6300×10 -8 c 2-1.5329×10 -6 c +1.2662×10 -5 R =0.9999 The K _m- c relationships show a strenuous inhibitory effect for Ni 2+ and a strenuous active effect for Ca 2+ .展开更多
The action of Cornu Cervi Pantotrichum (CCP), Cornu Cervi (CC) and Cornu Saigae Tataricae (CST) on Escherichia coli growth were investigated using microcalorimetry to find the heat change regularity of microbial growt...The action of Cornu Cervi Pantotrichum (CCP), Cornu Cervi (CC) and Cornu Saigae Tataricae (CST) on Escherichia coli growth were investigated using microcalorimetry to find the heat change regularity of microbial growth. The similarity of thermogenic curves and thermodynamics parameters were investigated as evaluation index, such as the growth rate constant in the first expo- nential phase (k1), maximum power in the first exponential phase (P1), maximum power in the secondary exponential phase (P2), peak time in the first exponential phase (T1), peak time in the stationary phase (T2) and the total heat production in stage 1 (Q1), and the total heat production in stage 2 (Q2). Chemometric analysis was used as a reference for the bioactivity evaluation of medicinal animal horns. The results indicated that the similarity between CST and the control was smaller than that between CCP, CC and the control. Both CCP and CC could increase the heat in the microbial growth, whereas CST decreased it. The biotic thermal activity of different medicinal animal horns was objectively, qualitatively, and quantitatively evaluated by the similarity of thermogenic curves and thermodynamics parameters analysis.展开更多
By using an LKB2277 Bioactivity Monitor,we have detedrined the thermogenesis power cu-rves of four kinds of Brucellas S2(55007), M5 (55009),83-202,83-980. And established the thermokinetic equation for the process of ...By using an LKB2277 Bioactivity Monitor,we have detedrined the thermogenesis power cu-rves of four kinds of Brucellas S2(55007), M5 (55009),83-202,83-980. And established the thermokinetic equation for the process of cell growth inlilbited by the products of metabolism, as:From this equation, the rate constants of cell growth k [= k0(1 - β’ P0)] were obtained.This thermokinetic equation is very suitable fdr cell growth of separated culture and is very important for the study of bacterial limited growth and their characteristics.展开更多
The thermograms of Brucalles Br.10 and Br-981 have been deterAnned. From the thermograJns, a thermokinetic equation ln =lnb - kt could be established for the liAnted growth of bacteria. From this equation, the growth ...The thermograms of Brucalles Br.10 and Br-981 have been deterAnned. From the thermograJns, a thermokinetic equation ln =lnb - kt could be established for the liAnted growth of bacteria. From this equation, the growth constant k, the intial growth rate 6, the mean specific growth rate k/m, and the mean thermal power increasing rate Pmaxk/(2m + 2) were calculated. This equation is very significant for the study of bacteriaJ growth and their characteristics.展开更多
By using an LKB-2277 Bioactivity Monitor, we have deterthened the thermogenesis curves of two species of Brucellas arithmetic series growth. nom the thermogenesis curves, a thermokinetic equation as:could be establish...By using an LKB-2277 Bioactivity Monitor, we have deterthened the thermogenesis curves of two species of Brucellas arithmetic series growth. nom the thermogenesis curves, a thermokinetic equation as:could be established for bacterial arithmetic series growth in which the order of growth metabolism n=0. The mean specific rate constant of multiplication and the mean generation time G et al. were calculated. This model was compared with the exponentialmodel.展开更多
The thermograms of mitochondrial metabolism of two kinds of fishes have been determined. From the thermograms, a thermokinetic equation ln could be established for the mitochondrial metobolism. From this equation, the...The thermograms of mitochondrial metabolism of two kinds of fishes have been determined. From the thermograms, a thermokinetic equation ln could be established for the mitochondrial metobolism. From this equation, the rate constants of activity recovery and activity decline were calculated. This equation is very significant for the study of mitochondrial metabolism.展开更多
By using LKB2277 Bioactivity Monitor, we have determined the thermogenesis power curves of four kinds of bacteria: Brucella M5(55010), 83-980, 83-981 and E. coli. We have also derived the thermokinetic equation for th...By using LKB2277 Bioactivity Monitor, we have determined the thermogenesis power curves of four kinds of bacteria: Brucella M5(55010), 83-980, 83-981 and E. coli. We have also derived the thermokinetic equation for the process of bacterial growth, which was untypical "S" , unideal growth, as:From this equation, the rate constants of bacterial growth k wore botained.This thermokinetic equation is very suitable for cell growth of separated culture, in which the thermogenesis curve is untypical. The model propoted by equationl(1) has been compared with the exponential and logistic models. This thermokinetic equation is very significant for the study of bacterial limited growth and their characteristics.展开更多
Studies on the thermokinetic properties of model compound of Purple acid phosphatases (Na2[Fe2(μ-O)(μ-OAC)2(IDA)2].5H2O hydrolysis of ATP, at 37℃, pH=6.0 by usingLKB-2107 Batch microcalorimentry system. The Michael...Studies on the thermokinetic properties of model compound of Purple acid phosphatases (Na2[Fe2(μ-O)(μ-OAC)2(IDA)2].5H2O hydrolysis of ATP, at 37℃, pH=6.0 by usingLKB-2107 Batch microcalorimentry system. The Michaelis constant Km=(2.898 ± 0.195)x 10-4mol.L-1 and rate constant k2=(4.617±0.193) x 10-3.s-1 have been determined. The result hasbeen discussed.展开更多
文摘The reaction between Laccase and o methoxyphenol have been studied by LKB 2107 batch microcalorimetry system. Thermodynamic parameters Δ rH m , Δ G 0 , Δ G ≠ T ,) and kinetic parameters ( K m,k 2 ) have been determined. The process of the reaction has been analyzed from changes in energy by using the transition state theory. Two methods for enhancing catalytic power of Laccase are proposed. The results shown that formation of an enzyme substrate complex is“anticatalytic”. The enter and sole source of catalytic power is the stabilization of transition state; reactant state interactions are by nature inhibitory and only waste catalytic power.
文摘The molar reation enthalpy,the Michaelis constant and the observed rate constant of the reaction between the Rhus vernicifera laccase and p-phenylenediamine have been determined at 298. 15 K by LKB-2107 microcalorimetry system in 0.1 mol/L phosphate salt buffer (pH7. 4) to be △rHm=-136.36±0. 36kJ/mol, Km= 5. 58×10-3 mol/L and k1 =8. 63×10-3s-1, respectively. The catalyst activity of laccase withp-phenylenediamine as substrate has been determined to be EA=0. 045 IU in the experimental condition.The observed activation energy of non-enzymic step of the reaction, the Gibbs binding energy of the combination process of laccase and substrate have been also calculated. The physical significance of the determined parameters were discussed for different step of the reaction.
文摘The thermokinetic reduced extent equations of reversible inhibitions for Michaiels-Menten enzymatic reaction were deduced, and then the criteria for distingushing inhibition type was given and the methods for calculating kinetic parameters, KM,Ki and Urn were suggested. This theory was applied to inverstigate the inhibited thermokinetics of laccase-catalyzed oxidation of o-dihydroxybenzene by m-dihydroxybenzene. The experimental results show the inhibition belongs to reversible competitive type, KM=6.224×10-3 mol L-1, Ki=2. 363 × 10-2 mol. L-1.
文摘Microcalorimetric bioassay for acute cellular toxicity is based on metabolicheat production from cultured cells. The biological response to toxicants is the inhibition of theheat production rate in cells, and toxicity is expressed as the concentration of toxicant that is50% effective to this inhibition (IC_(50)). In this paper, the effect of Na_2SeO_3 on Bacillussubtilis growth was investigated at 37℃ by microcalorimetry. The relationship between growth rateconstants (k) and concentration of Na_2SeO_3(c) shows a logarithmic normal distribution, and IC_(50)is 20.3 μg/mL. All these thermokinetic information is readily obtained by an LKB 2277-204 heatconduction microcalorimeter. Microcalorimetry is a quantitative, inexpensive, and versatile methodfor toxicology research.
基金ProjectsupportedbytheNaturalScienceFoundationofShandongProvince (No .Y2 0 0 0B0 3 )
文摘With or without activation or inhibition of metal ion,the power-time curves of amylase catalyzed reaction were determined by a 2277 thermal activity monitor (Sweden). The Michaelis constant ( K ),apparent Michaelis constant ( K _m),maximum velocity ( v _m) and apparent maximum velocity ( v _ am ) of amylase catalyzed reaction were obtained using thermokinetic theory and reduced extent method. On the basis of data obtained,the following relationships between K _m and concentration of metal ion ( c ) were established: for inhibitor of Ni 2+ K _m=2.9648×10 -3 -1.3912×10 -4 cR =0.9998for inhibitor of Co 2+ K _m=1.0227×10 -3 +8.2676×10 -6 cR =0.9955for activator of Ca 2+ K _m=1.0630×10 -7 c 2-1.8311×10 -6 c +9.3058×10 -6 R =0.9999for activator of Li + K _m=5.6300×10 -8 c 2-1.5329×10 -6 c +1.2662×10 -5 R =0.9999 The K _m- c relationships show a strenuous inhibitory effect for Ni 2+ and a strenuous active effect for Ca 2+ .
基金supported by the National Natural Science Foundation of China (30625042 and 30873385)the Key Technology of the National Great New Drugs Development Project of China (2009ZX09502-003 and 2009ZX09308-005)
文摘The action of Cornu Cervi Pantotrichum (CCP), Cornu Cervi (CC) and Cornu Saigae Tataricae (CST) on Escherichia coli growth were investigated using microcalorimetry to find the heat change regularity of microbial growth. The similarity of thermogenic curves and thermodynamics parameters were investigated as evaluation index, such as the growth rate constant in the first expo- nential phase (k1), maximum power in the first exponential phase (P1), maximum power in the secondary exponential phase (P2), peak time in the first exponential phase (T1), peak time in the stationary phase (T2) and the total heat production in stage 1 (Q1), and the total heat production in stage 2 (Q2). Chemometric analysis was used as a reference for the bioactivity evaluation of medicinal animal horns. The results indicated that the similarity between CST and the control was smaller than that between CCP, CC and the control. Both CCP and CC could increase the heat in the microbial growth, whereas CST decreased it. The biotic thermal activity of different medicinal animal horns was objectively, qualitatively, and quantitatively evaluated by the similarity of thermogenic curves and thermodynamics parameters analysis.
文摘By using an LKB2277 Bioactivity Monitor,we have detedrined the thermogenesis power cu-rves of four kinds of Brucellas S2(55007), M5 (55009),83-202,83-980. And established the thermokinetic equation for the process of cell growth inlilbited by the products of metabolism, as:From this equation, the rate constants of cell growth k [= k0(1 - β’ P0)] were obtained.This thermokinetic equation is very suitable fdr cell growth of separated culture and is very important for the study of bacterial limited growth and their characteristics.
文摘The thermograms of Brucalles Br.10 and Br-981 have been deterAnned. From the thermograJns, a thermokinetic equation ln =lnb - kt could be established for the liAnted growth of bacteria. From this equation, the growth constant k, the intial growth rate 6, the mean specific growth rate k/m, and the mean thermal power increasing rate Pmaxk/(2m + 2) were calculated. This equation is very significant for the study of bacteriaJ growth and their characteristics.
文摘By using an LKB-2277 Bioactivity Monitor, we have deterthened the thermogenesis curves of two species of Brucellas arithmetic series growth. nom the thermogenesis curves, a thermokinetic equation as:could be established for bacterial arithmetic series growth in which the order of growth metabolism n=0. The mean specific rate constant of multiplication and the mean generation time G et al. were calculated. This model was compared with the exponentialmodel.
文摘The thermograms of mitochondrial metabolism of two kinds of fishes have been determined. From the thermograms, a thermokinetic equation ln could be established for the mitochondrial metobolism. From this equation, the rate constants of activity recovery and activity decline were calculated. This equation is very significant for the study of mitochondrial metabolism.
文摘By using LKB2277 Bioactivity Monitor, we have determined the thermogenesis power curves of four kinds of bacteria: Brucella M5(55010), 83-980, 83-981 and E. coli. We have also derived the thermokinetic equation for the process of bacterial growth, which was untypical "S" , unideal growth, as:From this equation, the rate constants of bacterial growth k wore botained.This thermokinetic equation is very suitable for cell growth of separated culture, in which the thermogenesis curve is untypical. The model propoted by equationl(1) has been compared with the exponential and logistic models. This thermokinetic equation is very significant for the study of bacterial limited growth and their characteristics.
文摘Studies on the thermokinetic properties of model compound of Purple acid phosphatases (Na2[Fe2(μ-O)(μ-OAC)2(IDA)2].5H2O hydrolysis of ATP, at 37℃, pH=6.0 by usingLKB-2107 Batch microcalorimentry system. The Michaelis constant Km=(2.898 ± 0.195)x 10-4mol.L-1 and rate constant k2=(4.617±0.193) x 10-3.s-1 have been determined. The result hasbeen discussed.
