کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1925829 1536416 2011 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Purification and characterization of cystathionine β-synthase bearing a cobalt protoporphyrin
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
Purification and characterization of cystathionine β-synthase bearing a cobalt protoporphyrin
چکیده انگلیسی

Human cystathionine β-synthase (CBS), a pivotal enzyme in the metabolism of homocysteine, is a pyridoxal-5′-phosphate-dependent enzyme that also contains heme, a second cofactor whose function is still unclear. One strategy for elucidation of heme function is its replacement with different metalloporphyrins or with porphyrins containing different substituent groups. This paper describes a novel expression approach and purification of cobalt CBS (CoCBS), which results in a high yield of fully active, high purity enzyme, in which heme is substituted by Co-protoporphyrin IX (CoPPIX). Metal content analysis showed that the enzyme contained 92% cobalt and 8% iron. CoCBS was indistinguishable from wild-type FeCBS in its activity, tetrameric oligomerization, PLP saturation and responsiveness to the allosteric activator, S-adenosyl-l-methionine. The observed biochemical and spectral characteristics of CoCBS provide further support for the suggestion that heme is involved in structural integrity and folding of this unusual enzyme.

Research highlights
► Novel approach for heme replacement with cobalt protoporphyrin IX.
► Cobalt-substituted CBS retains full activity and is biochemically indistinguishable from wild type CBS.
► Metal analysis shows 92% of heme substitution for cobalt protoporphyrin IX.
► The slow reduction of CoCBS suggests that a regulation of CBS activity by porphyrin’s redox status is unlikely.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Archives of Biochemistry and Biophysics - Volume 508, Issue 1, 1 April 2011, Pages 25–30
نویسندگان
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