Chemoinformatic Study and Bioevaluation of Tc-99m-Labeled N-Acetyl Neuraminic Acid in C6 Glioma Cells: Potential Role as a Radionuclide Imaging Probe.

Background: To date, the use of sialic acid that are reported to be elevated during malignancy has been largely unexplored for tumor imaging. The purpose of the present study was to study the modeled stable conformers of n-acetyl neuraminic acid (Neu5Ac) and its radiolabeled conjugate (Tc-99m-Neu5Ac) through computational chemistry approach and its bioevaluation in rat C6 cell lines.

Materials And Methods: The Neu5Ac was radiolabeled with Tc-99m using stannous reduction method and the radiochemical purity of Tc-99m-Neu5Ac was determined by instant thin layer chromatography.

Construction and conformational behavior of peptoids with cis-amide bond geometry: design of a peptoid with alternate φ, ψ values of inverse PP-II/PP-II and PP-I structures.

In peptoids due to the absence of amide protons, the backbone is devoid of hydrogen bond donor, linked by tertiary amide, which can be iso-energetic between cis and trans-amide bond geometry. The peptoids can be realized with cis amide bond if the side chain of ith residue can engage the carbonyl group of ith-1 residue in CH--O interactions. Simulations studies both in water and DMSO have been carried out.

Conformational study of N-methylated alanine peptides and design of Abeta inhibitor.

N-Methylation increases the proteolytic stability of peptides and leads to improved pharmacological and increased nematicidal property against plant pathogens. In this study, the quantum mechanical and molecular dynamic simulation approaches were used to investigate conformational behavior of peptides containing only N-methylated alanine (NMeAla) residues and N-methylated alanine and alanine residues at alternate positions. The amide bond geometry was found to be trans and the poly NMeAla peptides were shown to populate in the helical structure without hydrogen bond with phi, psi values of - 0, 90 degrees stabilized by carbonyl-carbonyl interactions.

Insights on the structural characteristics of Vim-TBS (58-81) peptide for future applications as a cell penetrating peptide.

The plasma membrane presents a remarkable barrier for the delivery of peptide and nucleic acid based drugs to the inside of cells. This restraint in the path of their development as therapeutic agents can be offset by their conjugation to cell penetrating peptides (CPPs) that can lead to an improved pharmacological profile. In this context, conformational behavior of Vimentin Tubulin Binding Site (TBS) peptide, Vim-TBS (58-81), was investigated for its acknowledged cell penetrating properties along with Trans-activating Tat (48-60) peptide and a pro-apoptogenic peptide of p21/WAFI protein (p10).

New type of helix and 2(7) ribbon structure formation in poly DeltaLeu peptides: construction of a single-handed template.

alpha,beta-Dehydroamino acid residues due to the presence of Calpha = Cbeta double bond influences the main chain and the side chain conformations. These residues have interesting chemical features including the increased resistance to enzymatic degradation. The chain length dependent conformational behavior of poly alpha,beta-dehydroleucine (DeltaLeu) peptides in both the pure forms Z and E and their various combinations like alternate ZE/EZ etc.