Porin from Marine Bacterium Marinomonas primoryensis KMM 3633T: Isolation, Physico-Chemical Properties, and Functional Activity.

Olga D Novikova,Tamara F Solov’Eva,Olga L Voronina,Natalia N Ryzhova,Ekaterina I Aksenova,Lyudmila A Romanenko,Olga Yu Portnyagina,Natalia Yu Kim,Valentina A Khomenko,Galina N Likhatskaya,Marina S Kunda

doi:10.3390/molecules25143131

Abstract

Marinomonas primoryensis KMM 3633T, extreme living marine bacterium was isolated from a sample of coastal sea ice in the Amursky Bay near Vladivostok, Russia. The goal of our investigation is to study outer membrane channels determining cell permeability. Porin from M. primoryensis KMM 3633T (MpOmp) has been isolated and characterized. Amino acid analysis and whole genome sequencing were the sources of amino acid data of porin, identified as Porin_4 according to the conservative domain searching. The amino acid composition of MpOmp distinguished by high content of acidic amino acids and low content of sulfur-containing amino acids, but there are no tryptophan residues in its molecule. The native MpOmp existed as a trimer. The reconstitution of MpOmp into black lipid membranes demonstrated its ability to form ion channels whose conductivity depends on the electrolyte concentration. The spatial structure of MpOmp had features typical for the classical gram-negative porins. However, the oligomeric structure of isolated MpOmp was distinguished by very low stability: heat-modified monomer was already observed at 30 °C. The data obtained suggest the stabilizing role of lipids in the natural membrane of marine bacteria in the formation of the oligomeric structure of porin.

Highlights

Gram-negative bacteria attract attention because of its extraordinary adaptability to natural environment as well as to anthropogenic, including nosocomial conditions
Bacterial cells of M. primoryensis KMM 3633T were grown at a temperature of 0, 6–8, and 24 ◦ C
Since porins as integral proteins exist in an intrinsically anisotropic environment within the bacterial membrane the main condition for maximizing protein extraction is the selection of a suitable detergent [25]

Summary

Introduction

Gram-negative bacteria attract attention because of its extraordinary adaptability to natural environment as well as to anthropogenic, including nosocomial conditions. Marine bacteria inhabit in oligotrophic environment with deficiency or lack of sunlight. Investigation of these bacteria revealed pressure regulation of the proteins expression [2], multiplication of genes important for metabolic pathways, and cell motility and other molecular mechanisms of the adaptation to extreme conditions [3]. Oil and petroleum products are the most common pollutants that disrupt and inhibit all life processes These products accumulate as difficult-oxidized forms of substances that change the direction of metabolism and the natural ratio of the number of microorganisms in ecosystems. This leads to a slowdown in the process of microbial purification of ocean waters

Methods

Results

Conclusion