Recommended Conferences

Genetic Engineering and Gene Therapy

Paris, France

Human Genetics and Genetic Disorders

Miami, USA

Tissue Engineering and Regenerative Medicine

Chicago, USA
Related Subjects

Characterization of bent helical conformations in polymorphic forms of a designed 18-residue peptide containing a central gly-pro segment

Author(s): Aravinda S,Shamala N,Karle IL, Balaram P


An 18-residue sequence Boc-Aib-Val-Ala-Leu-Aib-Val-Ala-Leu-Gly-Pro-Val-Ala-Leu-Aib-Val-Ala-Leu-Aib-OMe (UK18) was designed to examine the effect of introducing a Gly-Pro segment into the middle of a potentially helical peptide. The crystal structures of two polymorphic forms yielded a view of the conformation of three independent molecules. Form 1 (space group P2(1)2(1)2(1,) a = 14.620Å; b = 26.506Å, c = 28.858Å, Z = 4) has one molecule in the asymmetric unit, with one cocrystallized water molecule. Form 2 (space group P2(1)2(1)2(1,) a = 9.696Å; b = 19.641Å, c = 114.31Å, Z = 8) has two molecules in the asymmetric unit with four cocrystallized water molecules. In Form 1, residues 1 to 18 adopt ϕ,ψ values that lie in the right-handed helical (α(R) ) region of the Ramachandran map. Two residues, Leu (8) (ϕ = -92.0°, ψ = -7.5°) and Leu (17) (ϕ = -94.7°, ψ = -1.7°) adopt conformations that deviate significantly from helical values. In Form 2, molecule A, residues 2 to 16 lie in the α(R) region of ϕ,ψ space, with Leu (8) (ϕ = -94.9°, ψ = -2.9°) deviating significantly from helical values. Aib (1) and Aib (18) adopt left-handed (α(L)) helical conformation. Significant distortion is observed at Leu (17) (ϕ = -121.3°, ψ = -31.3°). Molecule B, Form 2, adopts a right-handed helix over residues 1 to 17. In all three molecules, a distinct bend in the helix is observed, with the bend angle values varying from 40.8° to 58.9°.

Similar Articles

Entrapement of a Water Wire in a Hydrophobic Peptide Channel with an Aromatic Lining

Author(s): Raghavender US, Bhaswati B, Indranil S, Rajagopal A, Shamala N, et al.

A designed beta-hairpin peptide

Author(s): Awasthi SK, Raghothama S, Balaram P

Beta-hairpins in proteins revisited: lessons for de novo design

Author(s): Gunasekaran K, Ramakrishnan C, Balaram P

NMR analysis of aromatic interactions in designed peptide beta-hairpins

Author(s): Mahalakshmi R, Raghothama S, Balaram P

The twists and turns of beta-peptides

Author(s): DeGrado WF, Schneider JP, Hamuro Y