Conformational analysis of N- and C-terminally protected tripeptide model glycyl-isoleucine-glycyl: An ab initio and DFT study

Authors

  • Behzad Chahkandi Department of Chemistry, Shahrood Branch, Islamic Azad University, Shahrood, Iran.
  • Bentolhoda Ashrafi Department of Chemistry, Shahrood Branch, Islamic Azad University, Shahrood, Iran
  • Mohammad Chahkandi Department of Chemistry, Hakim Sabzevari University, Sabzevar 96179-76487, Iran
Abstract:

An ab initio and density functional theory (DFT) study about conformational analysis of tripeptide model HCO−GLY−L−ILE−GLY−NH2 is presented. The tripeptide was scanned about initial, central, and final residues, separately while for every scanning procedure the two other residues had been kept in the β conformation and side chain (SC) dihedral angles were maintained on the gauche− (g‾) state (χ1, χ2 = ‒60). Conformers (L, L, D, D, D), (L, L, D), and (L, L, D, L) were found through scanning of the tripeptide about initial, central, and the last amino acids, respectively. At first, geometries of all conformers were optimized at the HF/6-31G (d) and B3LYP/6-31G (d) levels of theory. In the followings, their thermodynamic properties were obtained with performing of the frequency calculations at the same levels used for optimization. Finally, comparison of the calculated thermodynamic results of the found conformers to the tripeptide minima on Ramachandran map as the standard criteria proposed LLL as the most stable one.

Upgrade to premium to download articles

Sign up to access the full text

Already have an account?login

similar resources

conformational analysis of n- and c-terminally protected tripeptide model glycyl-isoleucine-glycyl: an ab initio and dft study

an ab initio and density functional theory (dft) study about conformational analysis of tripeptide model hco−gly−l−ile−gly−nh2 is presented. the tripeptide was scanned about initial, central, and final residues, separately while for every scanning procedure the two other residues had been kept in the β conformation and side chain (sc) dihedral angles were maintained on the gauche− (g‾) state (χ...

full text

Glycyl dehydropeptides of leucine, valine, and isoleucine.

Glycyl dehydropeptides of alanine, phenylalanine, norvaline, norleucine, and or-aminobutyric acid, and N-acetyl dehydropeptides of these amino acids, tyrosine, valine, and leucine have been prepared (l-3). Although the glycyl dehydropeptides were found to be hydrolyzed by tissue extracts, the only enzymatically susceptible N-acetyl dehydropeptide was that of alanine (1). In an effort to acquire...

full text

Ab-Initio and Conformational Analysis of a Potent VEGFR-2 Inhibitor: A Case Study on Motesanib

Vascular endothelial growth factor receptor-2 (VEGFR-2); a cell surface receptor for vascular endothelial growth factors, is a key pharmacological target involved in the cell proliferation/angiogenesis. It has been revealed that VEGFR-2 induces proliferation through activation of the extracellular signal-regulated kinases pathway. In this regard, targeting the VEGFR-2 has been considered as an ...

full text

Ab-Initio and Conformational Analysis of a Potent VEGFR-2 Inhibitor: A Case Study on Motesanib

Vascular endothelial growth factor receptor-2 (VEGFR-2); a cell surface receptor for vascular endothelial growth factors, is a key pharmacological target involved in the cell proliferation/angiogenesis. It has been revealed that VEGFR-2 induces proliferation through activation of the extracellular signal-regulated kinases pathway. In this regard, targeting the VEGFR-2 has been considered as an ...

full text

Theoretical Analysis on the Conformational Features of the HCO—Gly—L—Leu—NH2 Protected Dipeptide Motif: Ab initio and DFT Exploratory

For better understanding of conformational stability of the dipeptide model HCO—Gly—L—Leu—NH2,ab initio and DFT computations at HF/6-31G(4 6-311++G(d,p) and B3LYP/6-31G(d) levels oftheory were carried out. Geometry optimization of the dipeptide within the leucine (Leu) side chainangles (x2 ,x2) resulted in three stable conformations as followings: anti-anti, the most stable one,(Xi = 180°, x2 =...

full text

My Resources

Save resource for easier access later

Save to my library Already added to my library

{@ msg_add @}


Journal title

volume 2  issue 1

pages  68- 75

publication date 2014-06-01

By following a journal you will be notified via email when a new issue of this journal is published.

Hosted on Doprax cloud platform doprax.com

copyright © 2015-2023