ATP-Lipids-Protein Anchor and Energy Source in Two Dimensions
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- 作者：Lutz Schmitt and and Robert Tampé
- 刊名：Journal of the American Chemical Society
- 出版年：1996
- 出版时间：June 19, 1996
- 年：1996
- 卷：118
- 期：24
- 页码：5532 - 5543
- 全文大小：514K
- 年卷期：v.118,no.24(June 19, 1996)
- ISSN：1520-5126
文摘
The ubiquitous function of ATP as energyequivalent in nature has resulted in a common foldingpatternof ATP-binding proteins. Their binding pocket toleratesmodifications of the adenine ring to some extend, whereasthose of the triphosphate group strongly affect the binding affinity.In consequence, immobilized C8- andN6-modified ATP analogues are frequently used for affinity purification ofATPases or kinases. To combine this uniquerecognition principle with the fascinating properties of self-assembly,we have synthesized a novel class of hydrolyzableand nonhydrolyzable ATP-lipids where the nucleotides are covalentlyattached via C8- or N6-position of theadeninering to a synthetic lipid. These ATP-lipids were characterized byvarious enzyme assays in micellar solution, resultingin ATPase and competition activities that are comparable to their freecounterparts. The specific docking of actinas a model of an ATP-binding protein to ATP-lipid monolayers wasfollowed by film balance technique andepifluorescence microscopy. Based on this specific interaction,actin-supported membranes were generated to studyshape transitions of vesicular systems. Due to the coupling ofactin to ATP-lipid bilayers drastic changes in theviscoelastic properties and shape transitions were observed by phasecontrast microscopy. These results underlinethe properties of these novel ATP-lipids as protein anchor or energysource in two dimensions. They can be appliedeither to form phantom cells, actin-supported membranes or to orientand crystallize ATP-binding proteins at lipidinterfaces.