کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1272519 1496932 2007 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Protein influence on the plasma membrane dielectric properties: In vivo study utilizing dielectric spectroscopy and fluorescence microscopy
موضوعات مرتبط
مهندسی و علوم پایه شیمی الکتروشیمی
پیش نمایش صفحه اول مقاله
Protein influence on the plasma membrane dielectric properties: In vivo study utilizing dielectric spectroscopy and fluorescence microscopy
چکیده انگلیسی

We have investigated the origin of the dielectric response of the plasma membrane of living yeast cells (Saccharomyces cerevisiae) by using radiofrequency dielectric spectroscopy. The cells were genetically engineered to overexpress in the membrane of yeast cells a G protein-coupled receptor – the Sterile2-α factor receptor protein (Ste2p) – fused to the green fluorescent protein (GFP). Presence of the Ste2-GFP proteins in the plasma membrane was confirmed by exciting the cells at 476 nm and observing with a confocal microscope the emission characteristic of the GFP from individual cells. The dielectric behavior of cells suspended in KCl solution was analyzed over the frequency range 40 Hz–110 MHz and compared to the behavior of control cells that lacked the ability to express Ste2p. A two-shell electrical cell model was used to fit the data starting from known structural parameters and adjustable electrical phase parameters. The best-fit value for the relative permittivity of the plasma membrane showed no significant difference between cells expressing Ste2p (1.63 ± 0.11) and the control cells (1.75 ± 0.16). This result confirmed earlier predictions that the dielectric properties of the plasma membrane in the radiofrequency range mostly reflect the properties of the hydrophobic layer of the membrane, which is populated by the hydrocarbon tails of the phospholipids and hydrophobic segments of integral membrane proteins. We discuss ways by which dielectric spectroscopy can be improved to be used for tag-free detection of proteins on the membrane.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Bioelectrochemistry - Volume 70, Issue 2, May 2007, Pages 542–550
نویسندگان
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