کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
10533814 961894 2005 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
A fluorogenic substrate for the continuous assaying of aryl sulfatases
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آنالیزی یا شیمی تجزیه
پیش نمایش صفحه اول مقاله
A fluorogenic substrate for the continuous assaying of aryl sulfatases
چکیده انگلیسی
The most common fluorogenic substrate for assaying aryl sulfatases (ARSs) is 4-methylumbelliferyl sulfate (MUS). However, ARSs operate optimally at pH values that are less than the pKa (7.8) of the reaction product of MUS, 4-methylumbelliferone (4-MU). Thus, a major disadvantage of this assay is that it is usually run in a discontinuous mode due to the need for basification of the reaction mixture to achieve complete ionization of the phenolic products and maximum fluorescence. To circumvent this problem, 6,8-difluoro-4-methylumbelliferyl sulfate (DiFMUS) was prepared and examined as a substrate for ARSs. The product of the reaction is 6,8-difluoro-4-methylumbelliferone, a known coumarin with fluorescent properties equal to those of 4-MU, and has a pKa of 4.9. This allowed for the continuous assaying of human placental ARSs A, B, and C, which operate optimally between pH 5.0 and pH 7.0. Furthermore, DiFMUS exhibited a lower Km (up to 20-fold) for the ARSs than did MUS; for ARSA and ARSB, it exhibited a greater Vmax than did MUS. This substrate should have considerable utility for the continuous assay of ARS activity.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Analytical Biochemistry - Volume 340, Issue 1, 1 May 2005, Pages 80-88
نویسندگان
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