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The antibacterial activity of p-tert-butylcalix[6]arene and its effect on a membrane model: molecular dynamics and Langmuir film studies.

Author(s): Wrobel EC, de Lara LS, do Carmo TAS, Castellen P, Lazzarotto M, de Lázaro SR, Camilo A, Caseli L, Schmidt R, DeWolf CE, Wohnrath K

Phys Chem Chem Phys. 2020 Mar 03;: Authors: Wrobel EC, de Lara LS, do Carmo TAS, Castellen P, Lazzarotto M, de Lázaro SR, Camilo A, Caseli L, Schmidt R, DeWolf CE, Wohnrath K

Article GUID: 32124897
Computational insight into hydrogen persulfide and a new additive model for chemical and biological simulations

Author(s): Orabi EA; Peslherbe GH;

S-Sulfhydration of cysteine to the Cys-SSH persulfide is an oxidative post-translational modification that plays an important regulatory role in many physiological systems. Though hydrogen persulfide (H2S2) has recently been established as a signaling and c...

Article GUID: 31297500
Expanding the range of binding energies and oxidizability of biologically relevant S-aromatic interactions: imidazolium and phenolate binding to sulfoxide and sulfone

Author(s): Orabi EA; English AM;

Oxidation and protonation/deprotonation strongly impact intermolecular noncovalent interactions. For example, S-aromatic interactions are stabilized up to three-fold in the gas phase on oxidation of the sulfur ligand or protonation/deprotonation of the arom...

Article GUID: 31214677
Predicting structural and energetic changes in Met-aromatic motifs on methionine oxidation to the sulfoxide and sulfone

Author(s): Orabi EA; English AM;

Noncovalent interactions between Met and aromatic residues define a common Met-aromatic motif in proteins. Met oxidation to MetOn (n = 1 sulfoxide, n = 2 sulfone) alters protein stability and function. To predict the chemical and physical consequences of su...

Article GUID: 30168822
Structural organization and phase behaviour of meta-substituted dioctadecylaminobenzoquinones at the air/water interface.

Author(s): Behyan S, Gritzalis D, Schmidt R, Kebede E, Cuccia LA, DeWolf C

Phys Chem Chem Phys. 2019 Jan 30;21(5):2345-2350 Authors: Behyan S, Gritzalis D, Schmidt R, Kebede E, Cuccia LA, DeWolf C

Article GUID: 30657501
Title:The antibacterial activity of p-tert-butylcalix[6]arene and its effect on a membrane model: molecular dynamics and Langmuir film studies.
Authors:Wrobel EC,  de Lara LS,  do Carmo TAS,  Castellen P,  Lazzarotto M,  de Lázaro SR,  Camilo A,  Caseli L,  Schmidt R,  DeWolf CE,  Wohnrath K
Link:https://www.ncbi.nlm.nih.gov/pubmed/32124897?dopt=Abstract
DOI:10.1039/d0cp00432d
Category:Phys Chem Chem Phys
PMID:32124897
Dept Affiliation: CNSR
1 Department of Chemistry, Universidade Estadual de Ponta Grossa, Ponta Grossa, Par84030-900, Brazil. karen.woh@gmail.com.
2 Department of Physics, Universidade Estadual de Ponta Grossa, Ponta Grossa, Paraná 84030-900, Brazil.
3 Academic Department of Mathematic, Universidade Federal Tecnológica do Paraná - Campus Ponta Grossa, Ponta Grossa, Paraná 84016-210, Brazil.
4 Department of Organic Chemistry, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul 91501-970, Brazil.
5 Instituto de Ciências Ambientais, Químicas e Farmacêuticas, Universidade Federal de São Paulo, Diadema, São Paulo (SP) 09972-970, Brazil.
6 Department of Chemistry and Biochemistry and Concordia Centre for NanoScience Research, Concordia University, 7141 Sherbrooke Street West, Montreal, Québec H4B 1R6, Canada.

Description:

The antibacterial activity of p-tert-butylcalix[6]arene and its effect on a membrane model: molecular dynamics and Langmuir film studies.

Phys Chem Chem Phys. 2020 Mar 03;:

Authors: Wrobel EC, de Lara LS, do Carmo TAS, Castellen P, Lazzarotto M, de Lázaro SR, Camilo A, Caseli L, Schmidt R, DeWolf CE, Wohnrath K

Abstract

The antibacterial activity of a calixarene derivative, p-tert-butylcalix[6]arene (Calix6), was assessed and was shown not to inhibit the growth of E. coli, S. aureus and B. subtilis bacteria. With the aim of gaining more insights into the absence of antibacterial activity of Calix6, the interaction of this derivative with DPPG, a bacterial cell membrane lipid, was studied. Langmuir monolayers were used as the model membrane. Pure DPPG and pure Calix6 monolayers, as well as binary DPPG:Calix6 mixtures were studied using surface pressure measurements, compressional modulus, Brewster angle and fluorescence microscopies, ellipsometry, polarization-modulation infrared reflection absorption spectroscopy and molecular dynamics simulations. Thermodynamic properties of the mixed monolayers were additionally calculated using thermodynamic parameters. The analysis of isotherms showed that Calix6 significantly affects the DPPG monolayers, modifying the isotherm profile and increasing the molecular area, in agreement with the molecular dynamics simulations. The presence of Calix6 in the mixed monolayers decreased the interfacial elasticity, indicating that calixarene disrupts the strong intermolecular interactions of DPPG hindering its organization into a compact arrangement. At low molar ratios of Calix6, the DPPG:Calix6 interactions are preferentially attractive, due to the interactions between the hydrophobic tails of DPPG and the tert-butyl groups of Calix6. Increasing the proportion of calixarene generates repulsive interactions. Calix6 significantly affects the hydrophobic tail organization, which was confirmed by PM-IRRAS measurements. Calix6 appears to be expelled from the mixed films at a biologically relevant surface pressure, p = 30 mN m-1, indicating a low interaction with the cell membrane model related to the absence of antibacterial activity.

PMID: 32124897 [PubMed - as supplied by publisher]