کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1945590 1053269 2008 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Influence of salt on the structure of DMPG studied by SAXS and optical microscopy
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
Influence of salt on the structure of DMPG studied by SAXS and optical microscopy
چکیده انگلیسی

Aqueous dispersions of 50 mM dimyristoylphosphatidylglycerol (DMPG) in the presence of increasing salt concentrations (2–500 mM NaCl) were studied by small angle X-ray scattering (SAXS) and optical microscopy between 15 and 35 °C. SAXS data show the presence of a broad peak around q ∼ 0.12 Å− 1 at all temperatures and conditions, arising from the electron density contrasts within the bilayer. Up to 100 mM NaCl, this broad peak is the main feature observed in the gel and fluid phases. At higher ionic strength (250–500 mM NaCl), an incipient lamellar repeat distance around d = 90–100 Å is detected superimposed to the bilayer form factor. The data with high salt were fit and showed that the emergent Bragg peak is due to loose multilamellar structures, with the local order vanishing after ∼ 4d. Optical microscopy revealed that up to 20 mM NaCl, DMPG is arranged in submicroscopic vesicles. Giant (loose) multilamellar vesicles (MLVs) start to appear with 50 mM NaCl, although most lipids are arranged in small vesicles. As the ionic strength increases, more and denser MLVs are seen, up to 500 mM NaCl, when MLVs are the prevailing structure. The DLVO theory could account for the experimentally found interbilayer distances.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biochimica et Biophysica Acta (BBA) - Biomembranes - Volume 1778, Issue 4, April 2008, Pages 907–916
نویسندگان
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