Gram-negative bacteria and mitochondria are both covered by two distinct biological membranes. These membrane systems have been maintained during the course of evolution from an early evolutionary precursor. Both outer membranes accommodate channels of the porin family, which are designed for the uptake and exchange of metabolites, including ions and small molecules, such as nucleosides or suga...

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...

Title of Thesis: Investigation of the Basis for Persistent Porin Serotypes of Neisseria gonorrhoeae in Community Infections Lotisha Erin Garvin, Master Degree, 2006 Thesis directed by: Ann Jerse, Ph. D. Associate Professor, Department of Microbiology and Immunology Uniformed Services University Neisseria gonorrhoeae porin (por), a major outer membrane protein, has been studied extensively in va...

We have isolated an outer mitochondrial membrane (OMM) fraction from baker's yeast. Saccharomyces cerevisiae, that possesses porin activity and contains a major polypeptide of 29,000 daltons. By analogy to similar data for an OMM fraction from rat liver and mung bean [Zalman, L. S., Nikaido, N. & Kagawa, Y. (1980) J. Biol. Chem. 255, 1771-1774], the 29,000-dalton polypeptide of the isolated yea...

Mitochondrial outer membrane permeability is conferred by a family of porin proteins. Mitochondrial porins conduct small molecules and constitute one component of the permeability transition pore that opens in response to apoptotic signals. Because mitochondrial porins have significant roles in diverse cellular processes including regulation of mitochondrial ATP and calcium flux, we sought to d...

The porin (PorB) of Neisseria gonorrhoeae is an intriguing bacterial factor owing to its ability to translocate from the outer bacterial membrane into host cell membranes where it modulates the infection process. Here we report on the induction of programmed cell death after prolonged infection of epithelial cells with pathogenic Neisseria species. The underlying mechanism we propose includes t...

cDNA encoding porin of Neurospora crassa, the major protein component of the outer mitochondrial membrane, was isolated and the nucleotide sequence was determined. The deduced protein sequence consists of 283 amino acids (29,979 daltons) and shows sequence homology of around 43% to yeast porin; however, no significant homology to bacterial porins was apparent. According to secondary structure p...

We show that for two well-characterized regulatory circuits in Escherichia coli, Tn10 tetracycline resistance and porin osmoregulation, the transcriptional outputs in individual cells are graded functions of the applied stimuli. These systems are therefore examples of naturally occurring regulatory circuits that exhibit continuous control of transcription. Surprisingly, however, we find that po...

One potential vaccine strategy in the fight against meningococcal disease involves the exploitation of outer-membrane components of Neisseria lactamica, a commensal bacterium closely related to the meningococcus, Neisseria meningitidis. Although N. lactamica shares many surface structures with the meningococcus, little is known about the antigenic diversity of this commensal bacterium or the an...