کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1956656 1057865 2008 13 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Raft Composition at Physiological Temperature and pH in the Absence of Detergents
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
Raft Composition at Physiological Temperature and pH in the Absence of Detergents
چکیده انگلیسی

Biological rafts were identified and isolated at 37°C and neutral pH. The strategy for isolating rafts utilized membrane tension to generate large domains. For lipid compositions that led only to microscropically unresolvable rafts in lipid bilayers, membrane tension led to the appearance of large, observable rafts. The large rafts converted back to small ones when tension was relieved. Thus, tension reversibly controls raft enlargement. For cells, application of membrane tension resulted in several types of large domains; one class of the domains was identified as rafts. Tension was generated in several ways, and all yielded raft fractions that had essentially the same composition, validating the principle of tension as a means to merge small rafts into large rafts. It was demonstrated that sphingomyelin-rich vesicles do not rise during centrifugation in sucrose gradients because they resist lysis, necessitating that, contrary to current experimental practice, membrane material be placed toward the top of a gradient for raft fractionation. Isolated raft fractions were enriched in a GPI-linked protein, alkaline phosphatase, and were poor in Na+-K+ ATPase. Sphingomyelin and gangliosides were concentrated in rafts, the expected lipid raft composition. Cholesterol, however, was distributed equally between raft and nonraft fractions, contrary to the conventional view.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: - Volume 94, Issue 7, April 2008, Pages 2654–2666
نویسندگان
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