@article{open513,
          volume = {93},
          number = {11},
           month = {November},
          author = {Nigam Kumar and P Venugopalan and Raghuvansh Kishore},
            note = {Copyright of this article belongs to Wiley},
           title = {Crystallographically observed folded topology of an unsubstituted {\ensuremath{\gamma}}-aminobutyric acid incorporated in a model peptide: importance of a C--H???O interaction.},
       publisher = {Wiley},
            year = {2010},
         journal = {Biopolymers},
           pages = {927--31},
        keywords = {unsubstituted g-aminobutyric acid; unusual
folded conformation; X-ray diffraction; FT-IR;
hydrogen bonded structure},
             url = {http://crdd.osdd.net/open/513/},
        abstract = {To validate the existing hypothesis put forward by Navarro et al., we performed single crystal X-ray diffraction structural analysis of a designed model peptide incorporating an unsubstituted achiral {\ensuremath{\gamma}}-aminobutyric acid: Boc-Pro-{\ensuremath{\gamma}}-Abu-OH (1) lacking C-terminal amide group. The analysis established existence of an overall unusual tightly folded topology stabilized by a conventional N(i)???H--N(i + 1) and an unconventional C(i)--H???O(i) type intramolecular hydrogen bonding interactions, encompassing a five-membered and a six-membered ring motifs, respectively. Moreover, in conjunction with Fourier transform infrared (FT-IR) absorption study in solid KBr, the results provided evidence that two conventional and one unconventional noncovalent intermolecular interaction stabilize a right-handed helical architecture generated via molecular self-assembly by translating the symmetry related molecules along the crystallographic b axis. {\copyright} 2010 Wiley Periodicals, Inc. Biopolymers 93: 927-931, 2010.}
}