کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1943704 1537056 2006 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Reaction mechanism of bovine heart cytochrome c oxidase
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم کشاورزی و بیولوژیک دانش گیاه شناسی
پیش نمایش صفحه اول مقاله
Reaction mechanism of bovine heart cytochrome c oxidase
چکیده انگلیسی

The 1.9 Å resolution X-ray structure of the O2 reduction site of bovine heart cytochrome c oxidase in the fully reduced state indicates trigonal planar coordination of CuB by three histidine residues. One of the three histidine residues has a covalent link to a tyrosine residue to ensure retention of the tyrosine at the O2 reduction site. These moieties facilitate a four electron reduction of O2, and prevent formation of active oxygen species. The combination of a redox-coupled conformational change of an aspartate residue (Asp51) located near the intermembrane surface of the enzyme molecule and the existence of a hydrogen bond network connecting Asp51 to the matrix surface suggest that the proton-pumping process is mediated at Asp51. Mutation analyses using a gene expression system of the Asp51-containing enzyme subunit yield results in support of the proposal that Asp51 plays a critical role in the proton pumping process.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biochimica et Biophysica Acta (BBA) - Bioenergetics - Volume 1757, Issues 5–6, May–June 2006, Pages 395–400
نویسندگان
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