scholarly journals Sugar Derived Oxazolone Pseudotetrapeptide as γ-Turn Inducer and Anion-Selective Transporter

2019 ◽  
Author(s):  
Sachin S Burade ◽  
Sushil V Pawar ◽  
Tanmoy Saha ◽  
Navnath M Kumbhar ◽  
Amol S Kotmale ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Amino Acid ◽  
Molecular Modeling ◽  
Ion Selectivity ◽  
Conformational Study ◽  
Oxazole Ring ◽  
Selective Transport ◽  
Molecular Modeling Studies ◽  
Oxazolone Ring

The C3-tetrasubstituted furanoid sugar amino acid derived linear amino acid dipeptide 8 and tetrapeptide 9 on intra-molecular cyclization afforded oxazolone pseudo-peptides 1 and 2a, respectively, with formation of oxazole ring at the C-terminus. Conformational study of 2a showed seven membered intramolecular C=O×××HN (II) hydrogen bonding leading to the γ-turn conformation which is absent in the precursor tetrapeptide 9 thus indicating the role of oxazolone ring in γ-turn formation in 2a. This fact was supported by the molecular modeling studies. The oxazolone ring containing pseudo-tetrapeptide 2a was found to be better ion transporter than pseudodi-peptide1.The ion selectivity of 2a indicated Cl-anion-selective transport via the antiport mechanism.

scholarly journals Sugar-derived oxazolone pseudotetrapeptide as γ-turn inducer and anion-selective transporter

2019 ◽  
Vol 15 ◽  
pp. 2419-2427
Author(s):  
Sachin S Burade ◽  
Sushil V Pawar ◽  
Tanmoy Saha ◽  
Navanath Kumbhar ◽  
Amol S Kotmale ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Amino Acid ◽  
Molecular Modeling ◽  
Intramolecular Cyclization ◽  
Membered Ring ◽  
Conformational Study ◽  
Oxazole Ring ◽  
Solution State ◽  
Modeling Studies ◽  
Molecular Modeling Studies

The intramolecular cyclization of a C-3-tetrasubstituted furanoid sugar amino acid-derived linear tetrapeptide afforded an oxazolone pseudo-peptide with the formation of an oxazole ring at the C-terminus. A conformational study of the oxazolone pseudo-peptide showed intramolecular C=O···HN(II) hydrogen bonding in a seven-membered ring leading to a γ-turn conformation. This fact was supported by a solution-state NMR and molecular modeling studies. The oxazolone pseudotetrapeptide was found to be a better Cl−-selective transporter for which an anion–anion antiport mechanism was established.

scholarly journals Unnatural Amino Acid Mutagenesis Reveals the Critical Role of Hydrogen Bonding for Binding of Retigabine in the Pore of KCNQ Channels

2014 ◽  
Vol 106 (2) ◽  
pp. 143a
Author(s):  
Stephan A. Pless ◽  
Michael Yau ◽  
Jason D. Galpin ◽  
Christopher A. Ahern ◽  
Harley T. Kurata
Keyword(s):  
Hydrogen Bonding ◽  
Amino Acid ◽  
Critical Role ◽  
Unnatural Amino Acid ◽  
Kcnq Channels ◽  
Unnatural Amino Acid Mutagenesis ◽  
Amino Acid Mutagenesis

Role of hydrogen bonding in cellulose deformation: the leverage effect analyzed by molecular modeling

Cellulose ◽  
2016 ◽  
Vol 23 (4) ◽  
pp. 2315-2323 ◽  
Author(s):  
Cyrus Djahedi ◽  
Malin Bergenstråhle-Wohlert ◽  
Lars A. Berglund ◽  
Jakob Wohlert
Keyword(s):  
Hydrogen Bonding ◽  
Molecular Modeling ◽  
Leverage Effect

A water-soluble Pd(ii) complex with a terpyridine ligand: experimental and molecular modeling studies of the interaction with DNA and BSA; and in vitro cytotoxicity investigations against five human cancer cell lines

2016 ◽  
Vol 40 (11) ◽  
pp. 9081-9097 ◽  
Author(s):  
Farivash Darabi ◽  
Hassan Hadadzadeh ◽  
Jim Simpson ◽  
Azar Shahpiri
Keyword(s):  
Hydrogen Bonding ◽  
Molecular Modeling ◽  
Human Cancer ◽  
In Vitro Cytotoxicity ◽  
Water Soluble ◽  
Human Cancer Cell ◽  
Human Cancer Cell Lines ◽  
Hydrogen Bonding Interactions ◽  
Molecular Modeling Studies

[Pd(4-OHPh-tpy)Cl]Cl was prepared. The complex interacts with DNA via a combination of covalent, intercalation, and hydrogen bonding interactions.

scholarly journals Inhibitor-Sensitive AmpC β-Lactamase Variant Produced by an Escherichia coli Clinical Isolate Resistant to Oxyiminocephalosporins and Cephamycins

2004 ◽  
Vol 48 (7) ◽  
pp. 2652-2658 ◽  
Author(s):  
Yohei Doi ◽  
Jun-ichi Wachino ◽  
Masaji Ishiguro ◽  
Hiroshi Kurokawa ◽  
Kunikazu Yamane ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Structural Change ◽  
Amino Acid ◽  
Molecular Modeling ◽  
Urine Specimen ◽  
E Coli ◽  
Class A ◽  
Resistant Phenotype ◽  
Molecular Modeling Studies ◽  
Base Insertion

ABSTRACT Escherichia coli HKY28, a ceftazidime-resistant strain isolated from a urine specimen in Japan, produced an inhibitor-sensitive AmpC β-lactamase variant. The deduced amino acid sequence of the enzyme contained a number of substitutions and a tripeptide deletion (Gly286-Ser287-Asp288) compared with the sequence of native AmpC of E. coli. When the deletion was reverted by a 9-base insertion at the relevant site of ampC in the clone, the typical inhibitor-resistant phenotype of AmpC was restored, while at the same time the levels of resistance to ceftazidime, cefpirome, and cefepime were reduced eightfold or more. Molecular modeling studies indicated that a structural change took place in the H-10 helix as a result of the deletion, and this change caused an alteration of the substrate binding site, leading to a unique phenotype analogous to that of inhibitor-sensitive class A extended-spectrum β-lactamases. The degree of inhibition was greater with sulbactam and tazobactam than with clavulanic acid. To our knowledge, this is the first report to have characterized an E. coli ampC that encodes chromosomal AmpC β-lactamase sensitive to the available β-lactamase inhibitors.

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