Hiroyuki Souma, Yoko Shigehisa, H. Kurosu
Nov 26, 2008
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Influential Citations
3
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Journal
Journal of Molecular Structure
Abstract
Abstract We computed the optimized structure of sequential 18-mer copolypeptide H-(Ala-Gly) 9 -OH (C 45 H 74 N 18 O 19 ) adopting an right-handed α-helix (α R -helix) conformation with the basis set of DFT/6-31G(d), and then calculated the nuclear shieldings of the optimized structure with the basis set of DFT/6-311G(d,p). As a result, we confirmed highly accurate conformational parameters characteristic to the α R -helical H-(Ala-Gly) 9 -OH, which were identical with those of the individual Ala and Gly residues. Most of these parameters were fundamentally the same as those obtained for the optimized α R -helical H-(Ala) 18 -OH. Furthermore, it was found that the calculated isotropic 13 C and 15 N chemical shifts were dependent on the nature of individual amino acid residues, which were greatly in good agreement with those of α R -helical model copolypeptides consisting of l -alanine and glycine residues measured by high-resolution solid-state NMR.