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 =...

bcn compounds have been researched theoretically and experimentally widely. in this paper, weintroduce the theoretical prediction of ternary b-c-n compounds. nmr spectroscopy was employedextensively to study these ternary nanostructures. we discuss the utilization of chemical shiftinformation as well as ab initio calculations of nuclear shielding for h20134c9n4 structuredetermination. we calcul...

Well-defined unnatural dipeptide-alcohols based on a cis-2,5-disubstitued pyrrolidine backbone were synthesized from commercially available starting materials meso-diethyl-2,5-dibromoadipate, (S)-(-)-1-phenylethylamine, and phenylalaninol. The structures of these unnatural dipeptide-alcohols are supported by HRMS, 1H- and 13C-NMR spectroscopy. These unnatural dipeptide-alcohols can act as build...

Peptides are one of the best candidates for drug development due to their high specificity and low toxicity and porphyrins are significant macromolecules in biological systems with important roles. In this works ynthesis of dipeptide (histidine-β-alanine) was done by solid-phase peptide synthesis method (SPPS) and tetrakis(4-sulfonatophenyl)porphyrin (TPPS4) was synthesized by Adler method. The...

The self-assembly of the dendritic dipeptides (4-3,4-3,5)nG2-CH2-Boc-L-Tyr-L-Ala-OMe and their achiral dendritic alcohol (4-3,4-3,5)nG2-CH2OH precursors, both with n = 1-16, where n represents the number of methylenic units in the alkyl groups of the dendron, are reported. All chiral dendritic dipeptides and achiral dendritic alcohols self-assemble into helical porous columns that are stable in...

The self-assembly of low molecular weight gelators to form gels has enormous potential for cell culturing, optoelectronics, sensing, and for the preparation of structured materials. There is an enormous “chemical space” of gelators. Even within one class, functionalised dipeptides, there are many structures based on both natural and unnatural amino acids that can be proposed and there is a need...

We describe herein the refined high resolution x-ray structures of two components of the bacterial cell wall, muramic acid and muramyl dipeptide complexed to isolectin I from Lathyrus ochrus seeds. In both complexes, only the ring hydroxyl oxygen atoms of the bound sugar establish direct hydrogen bonds with isolectin I, as in the case of all the previously determined monosaccharide-lectin compl...

Understanding the protein main-chain conformational space forms the basis for the modelling of protein structures and for the validation of models derived from structural biology techniques. Presented here is a novel idea for a three-dimensional distance geometry-based metric to account for the fine details of protein backbone conformations. The metrics are computed for dipeptide units, defined...

Seven crystal structures of alanyl aminopeptidase from Neisseria meningitides (the etiological agent of meningitis, NmAPN) complexed with organophosphorus compounds were resolved to determine the optimal inhibitor-enzyme interactions. The enantiomeric phosphonic acid analogs of Leu and hPhe, which correspond to the P1 amino acid residues of well-processed substrates, were used to assess the imp...