Please use this identifier to cite or link to this item:
http://nopr.niscpr.res.in/handle/123456789/30394| Title: | Characterization of non-planar peptide groups in protein crystal structures |
| Authors: | Dasgupta, Anjan Kumar Majumdar, Rabi Bhattacharyya, Dhananjay |
| Keywords: | X-ray diffraction;Database analysis;Neutron diffraction;Non-planar peptide;Peptide bond;Protein crystal structure |
| Issue Date: | Oct-2004 |
| Publisher: | NISCAIR-CSIR, India |
| IPC Code: | C 07 K |
| Abstract: | Peptide groups are generally assumed to be planar in protein structure, due to 'rigid' partial double bond character of peptide bonds, thus the value of peptide torsion angle ω should be restricted to 180° for the usual/rans form of peptide unit. However, on analyzing the ultra-high resolution protein crystal database, we find that in some cases, ω deviates> 10° from its usual value of 180°, indicating significant non-planarity of peptide groups. Moreover, the non-planarity for most of the amino acids is found to be 'biased' towards values of ω smaller than 180°. Similar trend for ω is confirmed by the neutron diffraction data for proteins. The neutron diffraction database also reveals that non-planar peptide groups are generally correlated to 'pyramidal' structure of the peptide-nitrogen bonds. Consequently, the hydrogen atom of peptide group deviates from its planar position, as measured by the 'improper' torsion angle θ. Thus, we find that both the angles ω and θ point towards a significant amount of non-planarity of peptide groups, which cannot be ignored. The role of peptide non-planarity in protein function is, however, not yet clear. |
| Page(s): | 233-240 |
| ISSN: | 0975-0959 (Online); 0301-1208 (Print) |
| Appears in Collections: | IJBB Vol.41(5) [October 2004] |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| IJBB 41(5) 233-240.pdf | 1.47 MB | Adobe PDF | View/Open |
Items in NOPR are protected by copyright, with all rights reserved, unless otherwise indicated.