کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1410896 | 1501838 | 2010 | 7 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Cooperativity of multiple H-bonds in influencing structural and spectroscopic features of the peptide unit of proteins
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موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آلی
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Cooperativity of multiple H-bonds in influencing structural and spectroscopic features of the peptide unit of proteins Cooperativity of multiple H-bonds in influencing structural and spectroscopic features of the peptide unit of proteins](/preview/png/1410896.png)
چکیده انگلیسی
A glycine dipeptide is paired with one or more formamide molecules in a variety of different H-bonding configurations, monitoring the structural and spectroscopic features of the dipeptide via ab initio calculations. Of particular interest is the way in which the perturbations induced by a CHâ¯O H-bond between the dipeptide and a proton acceptor are themselves affected by the presence of other H-bonds to the dipeptide. It is found that whether or not these other H-bonds are present, the introduction of a CHâ¯O H-bond causes the C-H bond to shorten, and its stretching frequency is shifted to the blue. Also relatively unaffected is the NMR chemical shift of the CH proton which moves further downfield upon formation of the CHâ¯O H-bond. In contrast, the effect of this CHâ¯O H-bond upon the NH group of the dipeptide varies depending on whether or not there are other H-bonds present. Specific effects of cooperativity are less amenable to simple interpretation in that there are differences in behavior between the two conformations of the dipeptide examined.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Molecular Structure - Volume 976, Issues 1â3, 15 July 2010, Pages 49-55
Journal: Journal of Molecular Structure - Volume 976, Issues 1â3, 15 July 2010, Pages 49-55
نویسندگان
Steve Scheiner,