کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1177331 961987 2007 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Spectrophotometric determination of peptide transport with chromogenic peptide mimetics
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آنالیزی یا شیمی تجزیه
پیش نمایش صفحه اول مقاله
Spectrophotometric determination of peptide transport with chromogenic peptide mimetics
چکیده انگلیسی
A spectrophotometric assay to determine peptide transport has been developed. Using two chromogenic peptide mimetics, l-phenylalanyl-l-2-sulfanilylglycine (PSG) and l-phenylalanyl-l-3-thiaphenylalanine (PSP), the peptide transport patterns in individual cell species can be evaluated effectively. After the addition of PSG to a HeLa cell suspension, sulfanilic acid accumulated progressively inside, but not outside, the cells, demonstrating that PSG was transported wholly intact. The addition of PSP to the same cell suspension was followed immediately by extracellular thiophenol production. Measurement of the rate of thiophenol release thereby provided direct determination of PSP transport. The thiophenol release was consistent with Michaelis-Menten kinetics, with a Km of 0.016 mM and a Vmax of 5.07 nmol/min (1 × 106 cells/ml, pH 7.4, 37 °C). The resulting kinetic constants estimated were in agreement with values determined by single-substrate enzyme kinetics. Using PSP, transport kinetics of various dipeptides was examined by competitive spectrophotometry. As a result, dipeptides tested could be ranked in order of kinetic power for their transport.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Analytical Biochemistry - Volume 367, Issue 2, 15 August 2007, Pages 167-172
نویسندگان
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