Narayanaswamy Shamala

Crystal Structures of Peptide Enantiomers and Racemates: Probing Conformational Diversity in Heterochiral Pro-Pro Sequences (2008)

Saha, Indranil, Chatterjee, Bhaswati, Shamala, Narayanaswamy, Balaram, Padmanabhan

Multiple conformational states in heterochiral diproline sequences have been characterized in the solid state by the determination of the crystal structures of seven tripeptides in enantiomeric and...

Erratum: "Conformations of \beta -Amino Acid Residues in Peptides: X-Ray Diffraction Studies of Peptides Containing the Achiral Residue 1-Aminocyclohexaneacetic Acid, $\beta^{3.3}Ac_6c$" (2008)

Vasudev, Prema G, Rai, Rajkishor, Shamala, Narayanaswamy, Balaram, Padmanabhan

The author has brought to our attention the following revision for Table II of the article listed above, published in Biopolymers 2008, 90(2):138–150. See the revised table shown on the following...

Conformations of \beta-Amino Acid Residues in Peptides: X-Ray Diffraction Studies of Peptides Containing the Achiral Residue 1-Aminocyclohexaneacetic Acid, $\beta^{3,3}Ac_6c$ (2008)

Vasudev, Prema G, Rai, Rajkishor, Shamala, Narayanaswamy, Balaram, Padmanabhan

The conformational preferences of the 3,3-disubstituted \beta-amino acid residue, 1-aminocyclohexaneacetic acid $(\beta^{3,3}Ac_6c)$ have been investigated by determining the crystal structures of...

Designed Peptides with Homochiral and Heterochiral Diproline Templates as Conformational Constraints (2008)

Chatterjee, Bhaswati, Saha, Indranil, Raghothama, Srinivasarao, Aravinda, Subrayashastry, Rai, Rajkishor, Shamala, Narayanaswamy, ...

Diproline segments have been advanced as templates for nucleation of folded structure in designed peptides. The conformational space available to homochiral and heterochiral diproline segments has...

Tryptophan Rich Peptides: Influence of Indole Rings on Backbone Conformation (2007)

Mahalakshmi, Radhakrishnan, Sengupta, Anindita, Raghothama, Srinivasarao, Shamala, Narayanaswamy, Balaram, Padmanabhan

Synthetic peptides with defined secondary structure scaffolds, namely hairpins and helices, containing tryptophan residues, have been investigated in this study to probe the influence of a large...

Hybrid Peptides: Expanding the \beta Turn in Peptide Hairpins by the Insertion of \beta-, \gamma-, and \delta-Residues (2007)

Rai, Rajkishor, Vasudev, Prema G, Ananda, Kuppanna, Raghothama, Srinivasarao, Shamala, Narayanaswamy, Karle, Isabella L, ...

The \beta turn segment in designed peptide hairpins has been expanded by the insertion of \beta-, \gamma- and \delta amino acids at the i+2 position. The model octapeptides...

Structural studies of model peptides \beta-, \gamma- containing and \delta- amino acids (2006)

Sengupta, Anindita, Aravinda, Subrayashastry, Shamala, Narayanaswamy, Raja, Muruga Poopathi K, Balaram, Padmanabhan

The crystal structures of five model peptides Piv-Pro-Gly-NHMe (1), Piv-Pro-\beta Gly-NHMe (2), Piv-Pro- \beta Gly-OMe (3), Piv-Pro- \delta Ava-OMe (4) and Boc-Pro- \gamma Abu-OH (5) are described...

$C_{9}$ Helices and Ribbons in \gamma-Peptides: Crystal Structures of Gabapentin Oligomers$^{*}^{*}$ (2005)

Vasudev, Prema G, Shamala, Narayanaswamy, Ananda, Kuppanna, Balaram, Padmanabhan

The insertion of additional atoms into \alpha -polypeptide backbones by the introduction of \beta, \gamma, and higher \omega amino acid residues expands the range of polypeptide secondary...

Structure and Assembly of Designed ‚beta-Hairpin Peptides in Crystals as Models for beta-Sheet Aggregation (2004)

Aravinda, Subrayashastry, Harini, Veldore Vidya, Shamala, Narayanaswamy, Das, Chittaranjan, Balaram, Padmanabhan

De noVo designed ‚b-hairpin peptides have generally been recalcitrant to crystallization. The crystal structures of four synthetic peptide ‚b-hairpins, Boc-Leu-Val-Val-DPro-Gly-Leu-Phe-Val-OMe...

Hydrogen-Bond Lengths in Polypeptide Helices: No Evidence for Short Hydrogen Bonds (2004)

Aravinda, Subrayashastry, Datta, Saumen, Shamala, Narayanaswamy, Balaram, Padmanabhan

The $3_1_0$ helix and \alpha helix are closely related secondary structures observed in polypeptides. The $3_1_0$ helix is characterized by successive $4\rightarrow1$ $(C_1_0)$ hydrogen bonds...

Phosphoprotein of the Rinderpest Virus Forms a Tetramer through a Coiled Coil Region Important for Biological Function (2004)

Rahaman, Abdur, Srinivasan, Naryanaswamy, Shamala, Narayanaswamy, Shaila, Melkote Subbarao

Phosphoprotein (P) of negative sense RNA viruses functions as a transcriptional transactivator of the viral polymerase (L). We report here the characterization of oligomeric P protein of rinderpest...

Probing the Role of the C-H…O Hydrogen Bond Stabilized Polypeptide Chain Reversal at the C-terminus of Designed Peptide Helices. Structural Characterization of Three Decapeptides (2003)

Aravinda, Subrayashastry, Shamala, Narayanaswamy, Bandyopadhyay, Abhishek, Balaram, Padmanabhan

The structural characterization in crystals of three designed decapeptides containing a double D-segment at the C-terminus is described. The crystal structures of the peptides Boc-Leu-Aib-Val-Xxx-...

\alpha-\gamma Hybrid Peptides that Contain the Conformationally Constrained Gabapentin Residue: Characterization of Mimetics of Chain Reversals (2003)

Aravinda, Subrayashastry, Ananda, Kuppanna, Shamala, Narayanaswamy, Balaram, Padmanabhan

The crystal structures of four dipeptides that contain the stereochemically constrained gamma-amino acid residue gabapentin (1-(aminomethyl) cyclohexaneacetic acid Gpn) are described. The molecular...

Aromatic-Aromatic Interactions in Crystal Structures of Helical Peptide Scaffolds Containing Projecting Phenylalanine Residues (2003)

Aravinda, Subrayashastry, Shamala, Narayanaswamy, Das, Chittaranjan, Sriranjini, Arumugam, Karle, Isabella L, Balaram, Padmanabhan

Aromatic-aromatic interactions between phenylalanine side chains in peptides have been probed by the structure determination in crystals of three peptides: Boc-Val-Ala-Phe-Aib-Val-Ala-Phe-Aib-OMe, I;...

Probing the Role of the C-H···O Hydrogen Bond Stabilized Polypeptide Chain Reversal at the C-terminus of Designed Peptide Helices. Structural Characterization of Three Decapeptides (2003)

Aravinda, Subrayashastry, Shamala, Narayanaswamy, Bandyopadhyay, Abhishek, Balaram, Padmanabhan

The structural characterization in crystals of three designed decapeptides containing a double D-segment at the C-terminus is described. The crystal structures of the peptides...

A right handed peptide helix containing a central double D-amino acid segment (2002)

Aravinda, Subrayashastry, Shamala, Narayanaswamy, Desiraju, Shrilakshmi, Balaram, Padmanabhan

The crystal structure of the 13 residue peptide Boc-Leu-Aib-Val-Ala-Leu-Aib-Val-DAla-DLeu-Aib-Leu-Aib-Val-OMe reveals a continuous helical conformation providing an unambiguous characterization of...

A Crystalline beta-Hairpin Peptide Nucleated by a Type I’ Aib-D-Ala beta-Turn: Evidence for Cross-Strand Aromatic Interactions (2002)

Aravinda, Subrayashastry, Shamala, Narayanaswamy, Rajkishore, Rai, Gopi, Hosahudya N, Balaram, Padmanabhan

Recent progress in the design of beta-hairpin peptides[1] and beta-sheet models has been based on the ability to nucleate reverse turns of the appropriate stereochemistry. D-Pro-Gly[2] and to a...

The $3_{10}$ helical conformation of a pentapeptide containing \alpha-aminoisobutyric acid (Aib): X-ray crystal structure of $Tos-{(Aib)}_5-OMe$ (1978)

Shamala, Narayanaswamy, Nagaraj, Ramakrishnan, Balaram, Padmanabhan

The pentapeptide $Tos-{(Aib)}_5-OMe$ adopts a $3_{10}$ helical conformation in the solid state, with three consecutive Type III \beta-turns stabilised by intramolecular hydrogen bonds.