1hvd
From Proteopedia
STRUCTURAL AND ELECTROPHYSIOLOGICAL ANALYSIS OF ANNEXIN V MUTANTS. MUTAGENESIS OF HUMAN ANNEXIN V, AN IN VITRO VOLTAGE-GATED CALCIUM CHANNEL, PROVIDES INFORMATION ABOUT THE STRUCTURAL FEATURES OF THE ION PATHWAY, THE VOLTAGE SENSOR AND THE ION SELECTIVITY FILTER
Structural highlights
Disease[ANXA5_HUMAN] Defects in ANXA5 are associated with susceptibility to pregnancy loss, recurrent, type 3 (RPRGL3) [MIM:614391]. A common complication of pregnancy, resulting in spontaneous abortion before the fetus has reached viability. The term includes all miscarriages from the time of conception until 24 weeks of gestation. Recurrent pregnancy loss is defined as 3 or more consecutive spontaneous abortions.[1] Function[ANXA5_HUMAN] This protein is an anticoagulant protein that acts as an indirect inhibitor of the thromboplastin-specific complex, which is involved in the blood coagulation cascade. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedAnnexin V binds to phospholipids in a calcium-dependent manner and exhibits calcium channel activity in vitro. We prepared a variety of mutants yielding information about the structure-function relationship of the ion channel activity. All mutants were characterized by X-ray crystallography, electron microscopy and electrophysiological measurements. Their structures are insignificantly changed whereas their electrophysiological properties are drastically different. Glu95, located in the central hydrophilic pore of the molecule, is crucial for the ion selectivity filter as its exchange leads to reduced calcium and increased sodium conductance. The removal of Glu17, located on the protein surface and far from the ion conduction pathway, leads to the appearance of a second conductance level of 9 pS in addition to the conductance level of about 30 pS in the wild-type molecule. This was also the case for Glu78, which is part of a weak calcium binding site. The exchange of Glu17 and Glu78 produced a mutant retaining only the smaller conductance level. We conclude that these two residues influence the angle between the two halves of the molecule, which determines the diameter of the ion conduction pathway, thereby leading to the occurrence of a second conductance level. Structural and electrophysiological analysis of annexin V mutants. Mutagenesis of human annexin V, an in vitro voltage-gated calcium channel, provides information about the structural features of the ion pathway, the voltage sensor and the ion selectivity filter.,Burger A, Voges D, Demange P, Perez CR, Huber R, Berendes R J Mol Biol. 1994 Apr 8;237(4):479-99. PMID:8151707[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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