期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1986
卷号：83
期号：5
页码：1315-1319
DOI：10.1073/pnas.83.5.1315
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Surfacing and membrane-penetrating ability of vinculin and bovine serum albumin have been studied on a macroscopic level by means of a Langmuir film balance and on a molecular level by means of infrared attenuated total reflection spectroscopy. It is suggested that the driving force of the nonspontaneous process of membrane penetration by native vinculin is the spontaneous formation of rigid vinculin monolayers in the membrane. Lateral adhesion of vinculin molecules results from the formation of intermolecular pleated-sheet structures. Vinculin surface activity was found to result from an alpha-helical segment oriented approximately perpendicular to plane of the membrane. There is a conformational equilibrium between this helix and random structure. High ionic strength (110 mM) favors helix formation that leads to the greater than 100-fold enhancement of surfacing velocity relative to the velocity observed at a lower ionic strength (10 mM). Vinculin has a second helical segment oriented parallel to the plane of the membrane that is in a conformational equilibrium with the pleated-sheet structure.
