Ray, Sudipta, Hegde, Raghurama P, Das, Apurba Kumar, Shamala, N, Banerjee, Arindam
The design and construction of nanostructured materials using proper self-assembling molecular building blocks is a real challenge to scientists. Here, we present the formation of a new...
Tryptophan-containing peptide helices: interactions involving the indole side chain (2005)
Mahalakshmi, R, Sengupta, A, Raghothama, S, Shamala, N, Balaram, P
TTwo designed peptide sequences containing Trp residues at positions i and i + 5 ( Boc- Leu- Trp- Val- Ala- Aib- Leu- Trp- Val- OMe, 1) as well as i and i + 6 ( Boc- Leu- Trp- Val- Aib- Ala- Aib-...
Das, Apurba Kumar, Haldar, Debasish, Hegde, Raghurama P, Shamala, N, Banerjee, Arindam
Single crystal X-ray diffraction studies on the water soluble, synthetic tetrapeptide Tyr(1)-Aib(2)-Tyr(3)-Val(4) with a non-coded amino acid residue (Aib: $\alpha$-amino isobutyric acid) reveal that...
Sengupta, A, Mahalakshmi, R, Shamala, N, Balaram, P
The crystal structures of the peptides, Boc-Leu-Trp-Val-OMe (1), Ac-Leu-Trp-Val-OMe (2a and 2b), Boc-Leu-Phe-Val-OMe (3), Ac-Leu-Phe-Val-OMe (4), and Boc-Ala-Aib-Leu-Trp-Val-OMe (5) have been...
Datta, Saumen, Rathore, RNS, Vijayalakshmi, S, Vasudev, Prema G, Rao, Balaji R, Balaram, P, ...
A pentapeptide, $Boc-Leu-Ac_8c-Ala-Leu-Ac_8c-OMe 1$, an octapeptide, $Boc-Leu-Ac_8c-Ala-Leu-Ac_8c-Ala-Leu-Ac_8c-OMe 2$ and a tripeptide, $Boc-Aib-Ac_8c-Aib-OMe 3$ containing the...
Non-protein amino acids in peptide design (2003)
Aravinda, S, Shamala, N, Roy, Rituparna S, Balaram, P
An overview of the use of non-protein amino acids in the design of conformationally well-defined peptides, based on work from the author’s laboratory, is discussed. The crystal structures of...
Ananda, K, Aravinda, S, Vasudev, Prema G, Raja, Muruga Poopathi K, Sivaramakrishnan, H, Nagarajan, K, ...
Gabapentin (1-(aminomethyl)cycloheaxaneacetic acid; Gpn) is a widely used anti-epileptic drug. The target site of action of Gpn remains controversial. Gpn can exist in two isomeric chair forms. The...
Rahaman, Abdur, Srinivasan, N, Shamala, N, Shaila, MS
We describe the properties of the two heptad repeats (HR1 and HR2) of the Peste des petits ruminants virus (PPRV) fusion protein (F) to obtain insights into the mechanism by which these repeats...
Structural Analysis of Peptide Helices Containing Centrally Positioned Lactic Acid Residues (2002)
Aravinda, S, Shamala, N, Das, Chittaranjan, Balaram, P
The effect of insertion of lactic acid (Lac) residues into peptide helices has been probed using specifically designed sequences. The crystal structures of 11-residue and 14-residue depsipeptides...
Aravinda, S, Shamala, N, Pramanik, Animesh, Das, Chittaranjan, Balaram, P
An unusual C-terminal conformation has been detected in a synthetic decapeptide designed to analyze the stereochemistry of helix termination in polypeptides. The crystal structure of the decapeptide...
Datta, Saumen, Uma, Manjappara V, Shamala, N, Balaram, P
The Schellman motif is a widely observed helix terminating structural motif in proteins, which is generated when the C-terminus residue adopts a left-handed helical (aL) conformation. The resulting...
Datta, Saumen, Shamala, N, Banerjee, Arindam, Balaram, P
The crystal structure of an acyclic pentapeptide, Boc-Gly-Gly-Leu-Aib-Val-OMe, reveals an extended conformation for the Gly-Gly segment, in contrast to the helical conformation determined earlier in...
Datta, Saumen, Shamala, N, Banerjee, Arindam, Pramanik, Animesh, Bhattacharjya, Surajit, Balaram, P
The Schellman motif is a widely observed, helix terminating structural motif in proteins, which is achieved by the adoption of a left-handed helical (alphaL) conformation by a C-terminus residue. The...
Datta, Saumen, Kaul, Ramesh, Rao, Balaji R, Shamala, N, Balaram, P
As part of a program to develop synthetic helix–linker–helix peptides the conformational properties of various linking segments are currently being investigated. The propensity of alpha,...
Banerjee, Arindam, Datta, S, Pramanik, Animesh, Shamala, N, Balaram, P
The helix is a common secondary structural element in proteins. Several subtypes of helical structures are possible, depending on the nature of the backbone hydrogen-bonding pattern. For short...
Structure of N-Nitroso-2,4-diphenyl-3-azabicyclo[3.3.1]nonane (1993)
Priya, V, Shamala, N, Viswamitra, MA, Ravindran, T, Jeyaraman, R
The title compound adopts a twin-chair conformation. The overall conformation is similar in both the molecules of the asymmetric unit. The phenyl rings are equatorially disposed with respect to the...
Apte, Madhuri, Shamala, N, Ramakrishnan, T
McGlynn and her co-workers have reported that among the Vietnamese refugees in Philadelphia and among Alaskan natives who are hepatitis B carriers, there is a statistically significant association...
Vishwanath, CK, Shamala, N, Easwaran, KRK, Vijayan, M
$M_r = 975.9$, orthorhombic, Pnna, a = 20.262 (3), b = 15.717 (2), $c = 15.038 (1) \AA$, $V = 4788.97 \AA^3$, z = 4, $D_ x = 1.35 Mg m ^-{3}$, $CuK\alpha$ radiation, $\lambda = 1.5418 \AA$, $\mu =...
Suguna, K, Ramakumar, S, Shamala, N, Prasad, Venkataram BV, Balaram, P
The crystal and molecular structures of two \alpha-aminoisohutyric acid (Aib)-containing diketopiperazines, cyclo(Aib-Aib) 1 and cyclo(Aib- L-Ile) 2, are reported. Cyclo(Aib-Aib) crystallizes in the...
Prasad, Venkataram BV, Shamala, N, Nagaraj, R, Balaram, P
Crystals of the title compound, $C_{20}H_{29}N_3O_6$, are monoclinic, space group ${P2}_1$, with a = 8.839 (3), b = 10.818 (3), c = 11.414 (2) A, \beta = 95.69 (2) deg, Z = 2; final R = 0.053. The...
Prasad, Venkataram BV, Shamala, N, Nagaraj, R, Chandrasekaran, R, Balaram, P
The crystal and molecular structure of N-benzyloxycarbonyl-\alpha-aminoisobutyryl-L-prolyl methylamide, the amino terminal dipeptide fragment of alamethicin, has been determined using direct methods....
Nagaraj, R, Shamala, N, Balaram, P
1H NMR studies of the protected \alpha-aminoisobutyric acid containing peptides Z-Aib-Pro-Aib-Ala-OMe and Z-Aib-Pro-Aib-OMe suggest that these molecules adopt well-defined conformations in solution....
Shamala, N, Nagaraj, R, Balaram, P
The molecular Structure of N-benzyloxycarbonyl-a-aminoisobutyryl-prolyl-a-aminoisobutyryl-alanyl methyl ester (z-Aib-Pro-Aib-Ala-OMe), the amino terminal tetrapeptide of alamethicin is reported. The...
Three-dimensional structure of flavocytochrome b2 from baker's yeast at 3.0-A resolution.
Xia, Z X, Shamala, N, Bethge, P H, Lim, L W, Bellamy, H D, Xuong, N H, ...
The structure of flavocytochrome b2 from baker's yeast was solved at 3.0-A resolution by the multiple isomorphous replacement method combined with solvent leveling procedures, using data collected...
Shamala, N, Lim, L W, Mathews, F S, McIntire, W, Singer, T P, Hopper, D J
The structure of p-cresol methylhydroxylase [4-cresol:(acceptor) oxidoreductase (methyl-hydroxylating), EC 1.17.99.1], a flavocytochrome c, has been determined at 6.0-A resolution. The structure...
Three-dimensional structure of flavocytochrome b2 from baker's yeast at 3.0-A resolution.
Xia, Z X, Shamala, N, Bethge, P H, Lim, L W, Bellamy, H D, Xuong, N H, ...
The structure of flavocytochrome b2 from baker's yeast was solved at 3.0-A resolution by the multiple isomorphous replacement method combined with solvent leveling procedures, using data collected...
Shamala, N, Lim, L W, Mathews, F S, McIntire, W, Singer, T P, Hopper, D J
The structure of p-cresol methylhydroxylase [4-cresol:(acceptor) oxidoreductase (methyl-hydroxylating), EC 1.17.99.1], a flavocytochrome c, has been determined at 6.0-A resolution. The structure...