کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10770146 | 1050829 | 2005 | 6 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Quinone reduction by Rhodothermus marinus succinate:menaquinone oxidoreductase is not stimulated by the membrane potential
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کلمات کلیدی
موضوعات مرتبط
علوم زیستی و بیوفناوری
بیوشیمی، ژنتیک و زیست شناسی مولکولی
زیست شیمی
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چکیده انگلیسی
Succinate:quinone oxidoreductase (SQR), a di-haem enzyme purified from Rhodothermus marinus, reveals an HQNO-sensitive succinate:quinone oxidoreductase activity with several menaquinone analogues as electron acceptors that decreases with lowering the redox midpoint potential of the quinones. A turnover with the low-potential 2,3-dimethyl-1,4-naphthoquinone that is the closest analogue of menaquinone, although low, can be detected in liposome-reconstituted SQR. Reduction of the quinone is not stimulated by an imposed K+-diffusion membrane potential of a physiological sign (positive inside the vesicles). Nor does the imposed membrane potential increase the reduction level of the haems in R. marinus SQR poised with the succinate/fumarate redox couple. The data do not support a widely discussed hypothesis on the electrogenic transmembrane electron transfer from succinate to menaquinone catalysed by di-haem SQRs. The role of the membrane potential in regulation of the SQR activity is discussed.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biochemical and Biophysical Research Communications - Volume 330, Issue 2, 6 May 2005, Pages 565-570
Journal: Biochemical and Biophysical Research Communications - Volume 330, Issue 2, 6 May 2005, Pages 565-570
نویسندگان
Andreia S. Fernandes, Alexander A. Konstantinov, Miguel Teixeira, Manuela M. Pereira,