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

Abstract

<jats:p>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.</jats:p>

Editorial to the Special Issue: “Dedicated to the 55th Anniversary of G.B. Elyakov Pacific Institute of Bioorganic Chemistry of the Far Eastern Branch of the Russian Academy of Sciences”

“…The study of biopolymers of marine origin remains extremely relevant. In order to study the channels of the outer membranes that determine cell permeability, Novikova et al [ 13 ] isolated and characterized the porin MpOmp from the extreme living marine bacterium Marinomonas primoryensis KMM 3633 T . It was concluded that lipid–protein interactions could be a factor that stabilizes the trimeric structure of MpOmp.…”