کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5859881 1133138 2015 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Characterization of the Gly45Asp variant of human cytochrome P450 1A1 using recombinant expression
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم محیط زیست بهداشت، سم شناسی و جهش زایی
پیش نمایش صفحه اول مقاله
Characterization of the Gly45Asp variant of human cytochrome P450 1A1 using recombinant expression
چکیده انگلیسی


- Gly45 is within a Pro-rich region of CYP1A1, responsible for holoenzyme expression.
- A variant of CYP1A1, Gly45Asp, had lower content of heme than wild-type.
- The Gly45Asp variant showed a reduced enzyme activity than the wild-type.

Cytochrome P450 1A1 (CYP1A1) is a heme-containing enzyme involved in metabolism of xenobiotics. CYP1A1 containing a Gly45Asp substitution has not yet been characterized. Escherichia coli expressing the Gly45Asp variant, as well as the purified variant protein, had lower CYP (i.e., holoenzyme) contents than their wild-type (WT) equivalents. The purified variant protein had reduced heme contents compared with their WT equivalents. Enhanced supplementation of a heme precursor during culture did not increase CYP content in E. coli expressing the variant, but did for the WT. Substitution of Gly45 with other residues, especially those having large side chains, decreased CYP contents of E. coli expressing the variants to a considerable extent. A 3D structure of CYP1A1 indicates that Gly45, along with other residues of the PR region, interacts with Arg77 of β- strand 1-1, which indirectly interacts with heme. Substitution analyses suggest the importance of residues of the PR region and Arg77 in holoenzyme expression. E. coli membrane and mammalian microsomes expressing the Gly45Asp variant, as well as the purified variant protein, had reduced ethoxyresorufin O-dealkylation activities, compared with the WT equivalents. These findings suggest the Gly45Asp substitution results in a structural disturbance of CYP1A1, reducing its holoenzyme formation and catalytic activity.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Toxicology Letters - Volume 239, Issue 2, 3 December 2015, Pages 81-89
نویسندگان
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