کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2028810 1070444 2007 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Phenylalanine90 and phenylalanine93 are crucial amino acids within the estrogen binding site of the human UDP-glucuronosyltransferase 1A10
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
Phenylalanine90 and phenylalanine93 are crucial amino acids within the estrogen binding site of the human UDP-glucuronosyltransferase 1A10
چکیده انگلیسی

Human UDP-glucuronosyltransferase 1A10 has been identified as the major isoform involved in the biotransformation of a wide range of phenolic substrates, including native estrogens and their oxidized metabolites. Our recent studies point to the F90–M91–V92–F93 amino acid motif of UGT1A10, which was identified using photoaffinity labeling followed by LC–MS/MS analysis, as a key determinant of the binding of phenolic substrates. In this report, we have evaluated the role of F90, V92, and F93 in the recognition of estrogens by UGT1A10 using site-directed mutagenesis. Kinetic studies using five mutants revealed that F90 and F93 are critical residues for the recognition of all estrogen substrates. The substitution of F90 with alanine totally abolished the activity of this enzyme toward all the estrogens investigated. Overall, sequential removal for the aromatic ring (F to L) and of the hydrophobic chain (F to A and V to A) from amino acids 90, 92, and 93 effectively alters estrogen recognition. This demonstrates that individual features of the native and hydroxylated estrogens determine the specific binding properties of the compound within the binding site of the human UGT1A10 and the mutants. The resulting activities are completely abolished, unchanged, increased, or decreased depending on the structures of both the mutant and the substrate. The novel identification of UGT1A10 as the major isoform involved in the glucuronidation of all estrogens and the discovery of the importance of the FMVF motif in the binding of steroids will help to elucidate the molecular mechanism of glucuronidation, resulting in the design of more effective estrogen-based therapies.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Steroids - Volume 72, Issue 1, January 2007, Pages 85–94
نویسندگان
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