کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1945505 1053266 2008 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Insight into the location and dynamics of the annexin A2 N-terminal domain during Ca2+-induced membrane bridging
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
Insight into the location and dynamics of the annexin A2 N-terminal domain during Ca2+-induced membrane bridging
چکیده انگلیسی

Annexin A2 (AnxA2) is a Ca2+- and phospholipid-binding protein involved in many cellular regulatory processes. Like other annexins, it is constituted by two domains: a conserved core, containing the Ca2+ binding sites, and a variable N-terminal segment, containing sites for interactions with other protein partners like S100A10 (p11). A wealth of data exists on the structure and dynamics of the core, but little is known about the N-terminal domain especially in the Ca2+-induced membrane-bridging process. To investigate this protein region in the monomeric AnxA2 and in the heterotetramer (AnxA2-p11)2, the reactive Cys8 residue was specifically labelled with the fluorescent probe acrylodan and the interactions with membranes were studied by steady-state and time-resolved fluorescence. In membrane junctions formed by the (AnxA2-p11)2 heterotetramer, the flexibility of the N-terminal domain increased as compared to the protein in solution. In “homotypic” membrane junctions formed by monomeric AnxA2, acrylodan moved to a more hydrophobic environment than in the protein in solution and the flexibility of the N-terminal domain also increased. In these junctions, this domain is probably not in close contact with the membrane surface, as suggested by the weak quenching of acrylodan observed with doxyl-PCs, but pairs of N-termini likely interact, as revealed by the excimer-forming probe pyrene-maleimide bound to Cys8. We present a model of monomeric AnxA2 N-terminal domain organization in “homotypic” bridged membranes in the presence of Ca2+.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biochimica et Biophysica Acta (BBA) - Biomembranes - Volume 1778, Issue 2, February 2008, Pages 472–482
نویسندگان
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