The adsorption of 80S ribosome from rat liver on the surface of lipid monolayers was examined by the electron microscopy (EM) using a negative staining method. The results showed that a large number of ribosomes were ...The adsorption of 80S ribosome from rat liver on the surface of lipid monolayers was examined by the electron microscopy (EM) using a negative staining method. The results showed that a large number of ribosomes were adsorbed on the lipid membrane surfaces containing positively charged SA (octadecylamine), while few ribosomes were observed on surfaces of neutral or negatively charged lipid monolayers. The interaction of ribosome with positively charged monolayers was affected by the composition and ratio of the membrane lipids, and by the ionic strength and pH value of the subphase buffer. The results suggest that ribosome should be adsorbed on the membrane surface through electrostatic force.展开更多
Synaptotagmin Ⅰ(sytⅠ) is an abundant integral membrane protein of the synaptic vesicle and the C2A domain is an important functional domain in the cytoplasmic part of sytⅠ. C2A prefers to interact with plasmic me...Synaptotagmin Ⅰ(sytⅠ) is an abundant integral membrane protein of the synaptic vesicle and the C2A domain is an important functional domain in the cytoplasmic part of sytⅠ. C2A prefers to interact with plasmic membranes of neuron cells in vivo and such interaction is closely related to the sytⅠ physiological function as a Ca 2+ sensor in the Ca 2+ regulated neurotransmitter release. However, the interaction nature between C2A and phospholipids is not well understood. Monolayers at an air/water interface were used to study the interaction between C2A and a phospholipid membrane. The results show that C2A preferentially inserts into the negatively charged phosphatidylserine monolayer and Ca 2+ ions are required for the interaction. Electrostatic force is mostly responsible for the insertion of C2A into dipalmitoyl phosphatidylserine monolayers.展开更多
A monolayer technique was used to investigate the interaction between the ribosome inactivating protein trichosanthin (TCS) and phospholipid membrane. The adsorption experiments show that the negatively charged 1,2...A monolayer technique was used to investigate the interaction between the ribosome inactivating protein trichosanthin (TCS) and phospholipid membrane. The adsorption experiments show that the negatively charged 1,2 dipalmitoyl sn glycerol 3 phosphoglycerol (DPPG) causes obvious enrichment of TCS beneath the monolayer, indicating electrostatic attraction between TCS and the negatively charged phospholipid. When TCS was incorporated into the DPPG monolayer at low pH, it could not be completely squeezed out until the monolayer collapsed. The results suggest that the electrostatic attraction and the hydrophobic force are involved in the interaction between TCS and phospholipids at different stages. These findings may be correlated with the membrane translocation mechanism of TCS.展开更多
文摘The adsorption of 80S ribosome from rat liver on the surface of lipid monolayers was examined by the electron microscopy (EM) using a negative staining method. The results showed that a large number of ribosomes were adsorbed on the lipid membrane surfaces containing positively charged SA (octadecylamine), while few ribosomes were observed on surfaces of neutral or negatively charged lipid monolayers. The interaction of ribosome with positively charged monolayers was affected by the composition and ratio of the membrane lipids, and by the ionic strength and pH value of the subphase buffer. The results suggest that ribosome should be adsorbed on the membrane surface through electrostatic force.
文摘Synaptotagmin Ⅰ(sytⅠ) is an abundant integral membrane protein of the synaptic vesicle and the C2A domain is an important functional domain in the cytoplasmic part of sytⅠ. C2A prefers to interact with plasmic membranes of neuron cells in vivo and such interaction is closely related to the sytⅠ physiological function as a Ca 2+ sensor in the Ca 2+ regulated neurotransmitter release. However, the interaction nature between C2A and phospholipids is not well understood. Monolayers at an air/water interface were used to study the interaction between C2A and a phospholipid membrane. The results show that C2A preferentially inserts into the negatively charged phosphatidylserine monolayer and Ca 2+ ions are required for the interaction. Electrostatic force is mostly responsible for the insertion of C2A into dipalmitoyl phosphatidylserine monolayers.
基金Supported by the National Natural Science Foundation of China (No. 30 0 70 2 0 4 ) and the Graduate StudentFoundation of the Ministry of Education of China
文摘A monolayer technique was used to investigate the interaction between the ribosome inactivating protein trichosanthin (TCS) and phospholipid membrane. The adsorption experiments show that the negatively charged 1,2 dipalmitoyl sn glycerol 3 phosphoglycerol (DPPG) causes obvious enrichment of TCS beneath the monolayer, indicating electrostatic attraction between TCS and the negatively charged phospholipid. When TCS was incorporated into the DPPG monolayer at low pH, it could not be completely squeezed out until the monolayer collapsed. The results suggest that the electrostatic attraction and the hydrophobic force are involved in the interaction between TCS and phospholipids at different stages. These findings may be correlated with the membrane translocation mechanism of TCS.
