Neisserial porins are strong immune adjuvants and B cell activators. The effect of neisserial porin PorB on activation-induced cell death was investigated, as a potential additional mechanism of the porin's immunopotentiating ability. Neisserial porins interact with target cells to localize intracellularly in the mitochondrial compartment without negatively affecting cellular survival. Pretreat...

The outer membrane-spanning (Oms) proteins of Borrelia burgdorferi have been visualized by freeze-fracture analysis but, until recently, not further characterized. We developed a method for the isolation of B. burgdorferi outer membrane vesicles and described porin activities with single-channel conductances of 0.6 and 12.6 nS in 1 M KCI. By using both nondenaturing isoelectric focusing gel ele...

Both acquired and intrinsic mechanisms play a crucial role in Pseudomonas aeruginosa antibiotic resistance. Many clinically relevant resistance mechanisms result from changes in gene expression, namely multidrug efflux pump overproduction, AmpC β-lactamase induction or derepression, and inactivation or repression of the carbapenem-specific porin OprD. Changes in gene expression are usually asse...

The role of charges near the pore mouth has been discussed in theoretical work about ion channels. To introduce new negative charges in a channel protein, amino groups of porin from Rhodobacter capsulatus 37b4 were succinylated with succinic anhydride, and the precise extent and sites of succinylations and structures of the succinylporins determined by mass spectrometry and X-ray crystallograph...

The atomic force microscope (AFM) was used to image native OmpF porin and to detect the electrostatic potential generated by the protein. To this end the OmpF porin trimers from Escherichia coli was reproducibly imaged at a lateral resolution of approximately 0.5 nm and a vertical resolution of approximately 0.1 nm at variable electrolyte concentrations of the buffer solution. At low electrolyt...

Background. This study described various molecular and epidemiological characters determining antibiotic resistance patterns in Pseudomonas aeruginosa isolates. Methods. A total of 34 carbapenem-resistant P. aeruginosa clinical isolates were isolated from samples collected at a tertiary hospital in Riyadh, Saudi Arabia, from January to December 2011. Susceptibility testing, serotyping, molecula...

The proportion of hexokinase that is bound to the outer mitochondrial membrane is tissue specific and metabolically regulated. This study examined the role of the N,N-dicyclohexylcarbodiimide-binding domain of mitochondrial porin in binding to hexokinase 1. Selective proteolytic cleavage of porin protein was performed and peptides were assayed for their, effect on hexokinase I binding to isolat...

The unifying structural characteristic of members of the bacterial order Thermotogales is their toga, an unusual cell envelope that includes a loose-fitting sheath around each cell. Only two toga-associated structural proteins have been purified and characterized in Thermotoga maritima: the anchor protein OmpA1 (or Ompα) and the porin OmpB (or Ompβ). The gene encoding OmpA1 (ompA1) was cloned a...