کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
9002313 | 1118583 | 2005 | 8 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Determination of the potency and subunit-selectivity of ribonucleotide reductase inhibitors with a recombinant-holoenzyme-based in vitro assay
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کلمات کلیدی
DTTIn vitro assay - آزمایش درون آزمایشگاهیQSAR - بزرگسال EPR - تشدید پارامغناطیس الکترونElectron paramagnetic resonance - تشدید پارامغناطیس الکترونdithiothreitol - دیتیوتریتولQuantitative structure–activity relationship - رابطه ساختاری و فعالیت کمیRibonucleotide reductase - ریبونوکلئوتید ردوکتازsemicarbazide - سمیکاربازیدRibonucleotide reductase inhibitors - مهارکننده های ریبونوکلئوتید ردوکتازHydroxyurea - هیدروکسی اوره
موضوعات مرتبط
علوم پزشکی و سلامت
داروسازی، سم شناسی و علوم دارویی
داروشناسی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Ribonucleotide reductase (RR) is an important therapeutic target for anticancer drugs. The structure of human RR features a 1:1 complex of two homodimeric subunits, hRRM1 and hRRM2. p53R2 is a newly identified homologue of hRRM2. We have devised a holoenzyme-based in vitro assay for the determination of the potency and subunit-selectivity of small-molecule inhibitors of RR. The assay was implemented using two forms of recombinant RR (hRRM2/hRRM1 and p53R2/hRRM1) and based on their [3H]CDP reduction activity. Hydroxyurea was used to standardize the assay. We found that the activities of hRRM2/hRRM1 and p53R2/hRRM1 were decreased by hydroxyurea in a dose-dependent manner. The -NH-OH segment of hydroxyurea was shown to be essential for inhibition. In the presence of Fe(III) and reductants, less inhibition of enzymatic activity by hydroxyurea was observed, especially for p53R2/hRRM1. The potency of four hydroxyurea analogues (Schiff bases of hydroxysemicarbazide, SB-HSC) decreased in the order SB-HSC 21Â >Â SB-HSC 24Â >Â SB-HSC 2Â >Â hydroxyurea (HU)Â >Â SB-HSC 29. SB-HSC 2 and SB-HSC 24 inhibited p53R2/hRRM1 significantly more than hRRM2/hRRM1, whereas SB-HSC 21 and SB-HSC 29 showed low subunit-selectivity. Electron paramagnetic resonance (EPR) measurements showed that inhibition of RR was accompanied by reduction of its tyrosyl radical. The method was validated by comparison with data obtained using cell-based assays. We suggest that this novel recombinant-holoenzyme-based in vitro assay is a useful tool for the discovery of more potent and subunit-selective inhibitors of RR.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biochemical Pharmacology - Volume 69, Issue 4, 15 February 2005, Pages 627-634
Journal: Biochemical Pharmacology - Volume 69, Issue 4, 15 February 2005, Pages 627-634
نویسندگان
Jimin Shao, Bingsen Zhou, Lijun Zhu, Angel J. Di Bilio, Leila Su, Yate-Ching Yuan, Shijun Ren, Eric J. Lien, Jennifer Shih, Yun Yen,