porin


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porin

(pŏr′ĭn) [Gr. poros, passageway]
A channel-forming protein in cell membranes that facilitates the diffusion of water and small molecules in and out of the cell.

porin

a protein in the outer MEMBRANE of Gram-negative BACTERIA (see GRAM'S STAIN that allows the passage of small polar molecules across the membrane. The concentration gradient of each transported commodity is used to drive its movement through the membrane.
References in periodicals archive ?
The Mishing organisation, Takam Mishing Porin Kebang (TMPK), called for a 12-hour dawn-to-dusk Assam shutdown to oppose the eviction drive.
Complicating detection are organisms which are resistant to carbapenems due to other resistant mechanisms such as outer membrane porin mutations or up-regulated efflux pumps, often in combination with AmpC hyper production or ESBLs.
The outer membrane protein profile by SDS-PAGE suggested a change in the expression of the 46 kDa porin that could correspond to OprD porin.
AVYCAZ also demonstrated in vitro activity against Pseudomonas aeruginosa in the presence of some AmpC beta-lactamases, and certain strains lacking outer membrane porin.
Impermeability arising via the loss of outer membrane porin (OprD), upregulation of an active efflux pump (MexAB-OprM), and production of metallo-[beta]-lactamases (MBLs) are of great concern [4, 11].
Carbapenem resistance in Gram-negative bacteria can be result of production of [beta]-lactamase enzyme known as carbapenemase, expression of efflux pumps, porin loss, and alterations in PBPs.
They are, (I) reduction in drug uptake due to the loss of porin in the outer membrane, [sup][7],[21],[22] (II) increase in production of carbapenemase, [sup][10],[19],[23] and (III) combination with loss of porin in the outer membrane and production of extended spectrum beta-lactamase (ESBL).
The mechanism of imipenem resistance involves the production of specific carbapenemases as well as the loss of porin proteins (Domenech-Sanchez et al.
VIM and IMP; (f) non-expression of porin genes and/or efflux pump-based antibiotic resistance (17).
mitochondrial membrane porin pores in order to be converted back to ATP
Methods--We performed scanning electron microscopy (SEM) to determine structural and quantitative differences in biofilm produced by ackA (encoding acetate kinase), pta (encoding phosphotransacetylase), ackArcsB (encoding acetate kinase and regulator of capsule synthesis B), ackA-ompR (encoding acetate kinase and outer membrane porin regulator) and ackA-dcuR (encoding acetate kinase and regulator of (C4)-dicarboxylic acid megabolism) mutants, in comparison with their isogenic parent strain.