کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4012261 1261186 2007 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
UV filter decomposition. A study of reactions of 4-(2-aminophenyl)-4-oxocrotonic acid with amino acids and antioxidants present in the human lens
موضوعات مرتبط
علوم زیستی و بیوفناوری ایمنی شناسی و میکروب شناسی ایمونولوژی و میکروب شناسی (عمومی)
پیش نمایش صفحه اول مقاله
UV filter decomposition. A study of reactions of 4-(2-aminophenyl)-4-oxocrotonic acid with amino acids and antioxidants present in the human lens
چکیده انگلیسی

Deamination of UV filters, such as kynurenine (KN), in the human lens results in protein modification. Thermal reactions of the product of kynurenine deamination, 4-(2-aminophenyl)-4-oxocrotonic acid (CKA), with amino acids (histidine, lysine, methionine, tryptophan, tyrosine, cysteine) and antioxidants (ascorbate, NADH, glutathione reduced) were studied. The rate constants of the reactions under physiological conditions were measured. The rate constants of CKA addition to cysteine kCys = 36 ± 4 M−1 s−1 and to glutathione kGSH = 2.1 ± 0.2 M−1 s−1 are 4–5 orders of magnitude higher than the rate constants of CKA reactions with the other amino acids and antioxidants. The Arrhenius parameters for kCys and kGSH were determined: AGSH = (1.8 ± 0.7) × 105 M−1 s−1, EGSH = 29.2 ± 5.6 kJ mol−1, ACys = (2.7 ± 0.9) × 108 M−1 s−1, ECys = 40.4 ± 5.7 kJ mol−1. The large difference in frequency factors for kCys and kGSH is attributed to steric hindrance, peculiar to the bulky GSH molecule.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Experimental Eye Research - Volume 85, Issue 2, August 2007, Pages 242–249
نویسندگان
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