کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1194246 1492288 2012 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Gas-phase hydrogen deuterium exchange behavior of lysine and its homologs
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آنالیزی یا شیمی تجزیه
پیش نمایش صفحه اول مقاله
Gas-phase hydrogen deuterium exchange behavior of lysine and its homologs
چکیده انگلیسی

The gas-phase hydrogen/deuterium exchange behavior for protonated lysine and its three shorter homologs, ornithine (Orn), 2,4-diamino butanoic acid (Daba), and 2,3-diamino propanoic acid (Dapa) were studied in a modified LCQ-DECA ion trap mass spectrometer. The HDX behavior of protonated lysine has been studied previously by several groups. It undergoes five equivalent exchanges, corresponding to the hydrogen atoms attached to the protonated lysine side chain and amine terminus nitrogen, and one slower exchange corresponding to the COOH hydrogen. The shorter homologs also exchange all six labile hydrogen atoms but at different rates. Relative to protonated lysine, DapaH+ exchanges two times faster, DabaH+ exchanges slightly slower, and OrnH+ exchanges nearly 30 times more slowly. High-level hybrid density functional theory calculations attribute this difference to the increased barrier for the relay-type exchange mechanism in OrnH+, relative to the other homologs.

Figure optionsDownload high-quality image (84 K)Download as PowerPoint slideHighlights
► We determined HDX rate coefficients for lysine its three lower homologs.
► All four homologs exchange all six labile hydrogens for deuterium using D2O.
► The data are consistent with relay and flip–flop mechanisms.
► DapaH+ exchanges the fastest, LysH+ and DabaH+ are slower, and OrnH+ is 30–50 times slower.
► The exchange rates correlate with calculated HDX barriers at the B3LYP/6-31+G(d,p) level.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: International Journal of Mass Spectrometry - Volumes 330–332, 15 December 2012, Pages 200–206
نویسندگان
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