Lipid rafts are a dynamic microdomain structure found in recent years, enriched in sphin- golipids, cholesterol and particular proteins. The change of structure and function of lipid rafts could result in many disease...Lipid rafts are a dynamic microdomain structure found in recent years, enriched in sphin- golipids, cholesterol and particular proteins. The change of structure and function of lipid rafts could result in many diseases. In this work, the monolayer miscibility behavior of mixed systems of Egg-Sphingomyelin （ESM） with 1, 2-dioleoyl-sn-glycero-3-phosphocholine was in- vestigated in terms of mean surface area per molecule and excess molecular area AAex at certain surface pressure, surface pressure and excess surface pressure Arcex at certain mean molecular area. The stability and compressibility of the mixed monolayers was assessed by the parameters of surface excess Gibbs free energy AGex, excess Helmholtz energy AHex and elasticity. Thermodynamic analysis indicates AAex and ATrex in the binary systems with positive deviations from the ideal behavior, suggesting repulsive interaction. The max- imum of AGex and AHex was at the molar fraction of ESM of 0.6, demonstrating the mixed monolayer was more unstable. The repulsive interaction induced phase separation in the monolayer.展开更多
Adsorption reactions between surfaces of nanodiamond and nanosilica with diameter of 100 nm prepared as suspension solutions of 0.25μg/μL and lysozyme molecule with different concentrations of 7 mmol/L PPBS at pH=7,...Adsorption reactions between surfaces of nanodiamond and nanosilica with diameter of 100 nm prepared as suspension solutions of 0.25μg/μL and lysozyme molecule with different concentrations of 7 mmol/L PPBS at pH=7, 9, 11, and 13 have been investigated by fluores- cence spectroscopy. Adsorption reaction constants and coverages of lysozyme with different concentrations of 0-1000 nmol/L under the influences of different pH values have been ob- tained. Helicities and conformations of the adsorbed lysozyme molecules, free spaces of every adsorbed lysozyme molecule on the surfaces of nanopartieles at different concentrations and pH values have been deduced and discussed. The highest adsorption capabilities for both sys- tems and conformational efficiency of the adsorbed lysozyme molecule at pH=13 have been obtained. Lysozyme molecules can be prepared, adsorbed and carried with optimal activity and helicity, with 2 and 10 mg/m2 on unit nanosurface, 130 and 150 mg/g with respect to the weight of nanoparticle, within the linear regions of the coverages at around 150-250 nmol/L and four pH values for nanodiamond and nanosilica, respectively. They can be prepared in the tightest packed form, with 20 and 55 mg/m2, 810-1680 and 580-1100 mg/g at threshold concentrations and four pH values for nanodiamond and nanosilica, respectively.展开更多
Exposure to cigarette smoke is a major risk factor for cancer and cardiovascular disease. Thrombosis is regarded as the main reason for smoking-related car- diovascular disease. However, the detail mechanism of how sm...Exposure to cigarette smoke is a major risk factor for cancer and cardiovascular disease. Thrombosis is regarded as the main reason for smoking-related car- diovascular disease. However, the detail mechanism of how smoking promotes thrombosis is not fully under- stood. In this work, we investigated the impacts of one major cigarette carcinogens 4-（methylnitrosamino）-l-（3- pyridyl）-l-butanone （NNK） as well as its metabolite 4-（methylnitrosamino）- 1-（3-pyridyl）- 1-butanol （NNAL） on a key process in thrombosis regulation： thrombin- thrombomodulin （TM） binding. Atomic force microscopy based single-molecule force spectroscopy was applied to measure both in vitro and in vivo binding force of thrombin to TM in the absence and presence of NNK and NNAL respectively. The results revealed that NNK and NNAL can reduce the binding probability of TM and thrombin. The inhibition effect and underlying mechanism was further studied by molecular simulation. As indicated by our results, the cigarette carcinogens could cause a higher risk of thrombosis through the disruption of TM- thrombin interaction.展开更多
文摘Lipid rafts are a dynamic microdomain structure found in recent years, enriched in sphin- golipids, cholesterol and particular proteins. The change of structure and function of lipid rafts could result in many diseases. In this work, the monolayer miscibility behavior of mixed systems of Egg-Sphingomyelin （ESM） with 1, 2-dioleoyl-sn-glycero-3-phosphocholine was in- vestigated in terms of mean surface area per molecule and excess molecular area AAex at certain surface pressure, surface pressure and excess surface pressure Arcex at certain mean molecular area. The stability and compressibility of the mixed monolayers was assessed by the parameters of surface excess Gibbs free energy AGex, excess Helmholtz energy AHex and elasticity. Thermodynamic analysis indicates AAex and ATrex in the binary systems with positive deviations from the ideal behavior, suggesting repulsive interaction. The max- imum of AGex and AHex was at the molar fraction of ESM of 0.6, demonstrating the mixed monolayer was more unstable. The repulsive interaction induced phase separation in the monolayer.
文摘Adsorption reactions between surfaces of nanodiamond and nanosilica with diameter of 100 nm prepared as suspension solutions of 0.25μg/μL and lysozyme molecule with different concentrations of 7 mmol/L PPBS at pH=7, 9, 11, and 13 have been investigated by fluores- cence spectroscopy. Adsorption reaction constants and coverages of lysozyme with different concentrations of 0-1000 nmol/L under the influences of different pH values have been ob- tained. Helicities and conformations of the adsorbed lysozyme molecules, free spaces of every adsorbed lysozyme molecule on the surfaces of nanopartieles at different concentrations and pH values have been deduced and discussed. The highest adsorption capabilities for both sys- tems and conformational efficiency of the adsorbed lysozyme molecule at pH=13 have been obtained. Lysozyme molecules can be prepared, adsorbed and carried with optimal activity and helicity, with 2 and 10 mg/m2 on unit nanosurface, 130 and 150 mg/g with respect to the weight of nanoparticle, within the linear regions of the coverages at around 150-250 nmol/L and four pH values for nanodiamond and nanosilica, respectively. They can be prepared in the tightest packed form, with 20 and 55 mg/m2, 810-1680 and 580-1100 mg/g at threshold concentrations and four pH values for nanodiamond and nanosilica, respectively.
基金supported by the National Basic Research Program of China (2013CB933701, 2013CB933704)the National Natural Science Foundation of China (21127901)
文摘Exposure to cigarette smoke is a major risk factor for cancer and cardiovascular disease. Thrombosis is regarded as the main reason for smoking-related car- diovascular disease. However, the detail mechanism of how smoking promotes thrombosis is not fully under- stood. In this work, we investigated the impacts of one major cigarette carcinogens 4-（methylnitrosamino）-l-（3- pyridyl）-l-butanone （NNK） as well as its metabolite 4-（methylnitrosamino）- 1-（3-pyridyl）- 1-butanol （NNAL） on a key process in thrombosis regulation： thrombin- thrombomodulin （TM） binding. Atomic force microscopy based single-molecule force spectroscopy was applied to measure both in vitro and in vivo binding force of thrombin to TM in the absence and presence of NNK and NNAL respectively. The results revealed that NNK and NNAL can reduce the binding probability of TM and thrombin. The inhibition effect and underlying mechanism was further studied by molecular simulation. As indicated by our results, the cigarette carcinogens could cause a higher risk of thrombosis through the disruption of TM- thrombin interaction.
