The average aggregate number(N)of electrostatically stabilized aggregate(ESAg)composed of oppositely-charged long-chain molecules,i.e., sodium ω-[α-(nathphyl)ethoxyl]undecanoate(FP^-)and cetyltrimethyl ammonium chlo...The average aggregate number(N)of electrostatically stabilized aggregate(ESAg)composed of oppositely-charged long-chain molecules,i.e., sodium ω-[α-(nathphyl)ethoxyl]undecanoate(FP^-)and cetyltrimethyl ammonium chloride(CTAC),in aqueous solution at 25℃ has been measured to be 11 to 16 in the CTAC-concentration range of 11×10^(-5) M to 30×10^(-5) M at a fixed FP- concentration of 1.0×10^(-5)M by the photon counting method.展开更多
The coaggregating behavior of the cationic kinetic probe P16;with different types of surfactants are in complete agreement with predictions based on the newly proposed ESAg concept.
Hydr hobie一lipophilic interactions(HLI)will start to bri about the formationof simple aggregates(Ag,s)and eoa egates(CoAg,s)from neutral organie moleeuleswhich possess at least onefl ble chain with more than seven eH...Hydr hobie一lipophilic interactions(HLI)will start to bri about the formationof simple aggregates(Ag,s)and eoa egates(CoAg,s)from neutral organie moleeuleswhich possess at least onefl ble chain with more than seven eHZ grou ,1,2 at theeritieala egate eoncentration展开更多
The aggregation behavior of a cationic fluorescence probe 10-（4,7,10,13,16-pentaoxa- 1-azacyclooctadecylmethyl）anthracen-9-ylmethyl dodecanoate （1） was observed and studied by a fluorescence methodology in acidic ...The aggregation behavior of a cationic fluorescence probe 10-（4,7,10,13,16-pentaoxa- 1-azacyclooctadecylmethyl）anthracen-9-ylmethyl dodecanoate （1） was observed and studied by a fluorescence methodology in acidic and neutral conditions. By using the Py scale, differences between simple aggregates and micelles have been discussed. The stability of simple aggregates was discussed in terms of hydrophobic interaction and electrostatic repulsion. The absence of excimer emission of the anthrancene moiety of probe 1 in neutral condition was attributed to the photoinduced electron transfer mechanism instead of photodimerization.展开更多
Salt influences protein stability through electrostatic mechanisms as well as through nonpolar Hofmeister effects.In the present work,a continuum solvation based model is developed to explore the impact of salt on pro...Salt influences protein stability through electrostatic mechanisms as well as through nonpolar Hofmeister effects.In the present work,a continuum solvation based model is developed to explore the impact of salt on protein stability.This model relies on a traditional Poisson-Boltzmann(PB)term to describe the polar or electrostatic effects of salt,and a surface area dependent term containing a salt concentration dependent microscopic surface tension function to capture the non-polar Hofmeister effects.The model is first validated against a series of cold-shock protein variants whose salt-dependent protein fold stability profiles have been previously determined experimentally.The approach is then applied to HIV-1 protease in order to explain an experimentally observed enhancement in stability and activity at high(1M)NaCl concentration.The inclusion of the salt-dependent non-polar term brings the model into quantitative agreement with experiment,and provides the basis for further studies into the impact of ionic strength on protein structure,function,and evolution.展开更多
文摘The average aggregate number(N)of electrostatically stabilized aggregate(ESAg)composed of oppositely-charged long-chain molecules,i.e., sodium ω-[α-(nathphyl)ethoxyl]undecanoate(FP^-)and cetyltrimethyl ammonium chloride(CTAC),in aqueous solution at 25℃ has been measured to be 11 to 16 in the CTAC-concentration range of 11×10^(-5) M to 30×10^(-5) M at a fixed FP- concentration of 1.0×10^(-5)M by the photon counting method.
文摘The coaggregating behavior of the cationic kinetic probe P16;with different types of surfactants are in complete agreement with predictions based on the newly proposed ESAg concept.
文摘Hydr hobie一lipophilic interactions(HLI)will start to bri about the formationof simple aggregates(Ag,s)and eoa egates(CoAg,s)from neutral organie moleeuleswhich possess at least onefl ble chain with more than seven eHZ grou ,1,2 at theeritieala egate eoncentration
基金Project supported by the National Natural Science Foundation of China （No. 20272078） and Shanghai Municipal Science and Technology Commission （No. 03JC14083）.
文摘The aggregation behavior of a cationic fluorescence probe 10-（4,7,10,13,16-pentaoxa- 1-azacyclooctadecylmethyl）anthracen-9-ylmethyl dodecanoate （1） was observed and studied by a fluorescence methodology in acidic and neutral conditions. By using the Py scale, differences between simple aggregates and micelles have been discussed. The stability of simple aggregates was discussed in terms of hydrophobic interaction and electrostatic repulsion. The absence of excimer emission of the anthrancene moiety of probe 1 in neutral condition was attributed to the photoinduced electron transfer mechanism instead of photodimerization.
文摘Salt influences protein stability through electrostatic mechanisms as well as through nonpolar Hofmeister effects.In the present work,a continuum solvation based model is developed to explore the impact of salt on protein stability.This model relies on a traditional Poisson-Boltzmann(PB)term to describe the polar or electrostatic effects of salt,and a surface area dependent term containing a salt concentration dependent microscopic surface tension function to capture the non-polar Hofmeister effects.The model is first validated against a series of cold-shock protein variants whose salt-dependent protein fold stability profiles have been previously determined experimentally.The approach is then applied to HIV-1 protease in order to explain an experimentally observed enhancement in stability and activity at high(1M)NaCl concentration.The inclusion of the salt-dependent non-polar term brings the model into quantitative agreement with experiment,and provides the basis for further studies into the impact of ionic strength on protein structure,function,and evolution.
