Nagarajaram, HA and Paul, PKC and Ramanarayanan, K and Soman, KV and Ramakrishnan, C (1992) Conformational studies on beta-bend containing a cis peptide unit. In: International Journal of Peptide & Protein Research, 40 (5). pp. 383-394.Full text not available from this repository.
Conformational studies have been carried out on the X-cis-Pro tripeptide system (a system of three linked peptide units, in the trans-cis-trans configuration) using energy minimization techniques. For X, residues Gly, L-Ala, D-Ala and L-Pro have been used. The energy minima have been classified into different groups based upon the conformational similarity. There are 15, 20, 18 and 6 minima that are possible for the four cases respectively and these fall into 11 different groups. A study of these minima shows that, (i) some minima contain hydrogen bonds - either 4-->1 or 1-->2 type, (ii) the low energy minima qualify themselves as bend conformations, (iii) cis' and trans' conformations are possible for the prolyl residue as also the C(gamma)-endo and C(gamma)-exo puckerings, and (iv) for Pro-cis-Pro, cis' at the first prolyl residue is ruled out, due to the high energy. The available crystal structure data on proteins and peptides, containing cis-Pro segment have been examined with a view to find the minima that occur in solid state. The data from protein show that they fall under two groups. The conformation at X in X-cis-Pro is near extended when it is a non-glycyl residue. In both peptides and proteins there exists a preference for trans' conformation at prolyl residue over cis' when X is a non-glycyl residue. The minima obtained can be useful in modelling studies.
|Item Type:||Journal Article|
|Additional Information:||Copyright of this article belongs to Munksgaard Int Publ Ltd.|
|Keywords:||Bends, Beta; Cis-Prolyl, In Proteins, In Peptides; Conformation, Peptides;Energy Minimization;Hydrogen Bonds With Cis Units;Peptides, Cis Units;Tripeptides With Cis Units.|
|Department/Centre:||Division of Biological Sciences > Molecular Biophysics Unit|
|Date Deposited:||25 Jan 2011 06:04|
|Last Modified:||25 Jan 2011 06:04|
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