Characterization of the fusogenic properties of glyceraldehyde-3-phosphate dehydrogenase: fusion of phospholipid vesicles.
A fluorescence assay based on resonance energy transfer has been used to characterize the fusogenic properties of glyceraldehyde-3-phosphate dehydrogenase. The extent of phospholipid vesicles fusion induced by the protein increased with decreasing pH, being maximum at pH 4.5-5.0. Fusion reaction was temperature dependent with an activation energy of 10 Kcal/mol, and virtually completed within 1 min. at pH 5.0. Fusion is most efficient with vesicles bearing negative charge, however uncharged and even positively charged vesicles were fused. The negatively charged and uncharged vesicles showed the same pH dependence. These observations suggest the importance of hydrophobic interaction in the process of fusion, which was supported by a correlation between extent of fusion and exposure of hydrophobic region of the protein.
D000818:Animals; D004735:Energy Transfer; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008081:Liposomes; D009132:Muscles / Q000201:enzymology; D010712:Phosphatidic Acids; D010713:Phosphatidylcholines; D011817:Rabbits; D013050:Spectrometry, Fluorescence; D013816:Thermodynamics
D008081:Liposomes; D010712:Phosphatidic Acids; D010713:Phosphatidylcholines; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases