DipA, a pore-forming protein in the outer membrane of Lyme disease spirochetes exhibits specificity for the permeation of dicarboxylates.

Lyme disease Borreliae are highly dependent on the uptake of nutrients provided by their hosts. Our study describes the identification of a 36 kDa protein that functions as putative dicarboxylate-specific porin in the outer membrane of Lyme disease Borrelia. The protein was purified by hydroxyapatite chromatography from Borrelia burgdorferi B31 and designated as DipA, for dicarboxylate-specific porin A.

Oms38 is the first identified pore-forming protein in the outer membrane of relapsing fever spirochetes.

Relapsing fever is a worldwide, endemic disease caused by several spirochetal species belonging to the genus Borrelia. During the recurring fever peaks, borreliae proliferate remarkably quickly compared to the slow dissemination of Lyme disease Borrelia and therefore require efficient nutrient uptake from the blood of their hosts. This study describes the identification and characterization of the first relapsing fever porin, which is present in the outer membranes of B.

An RND-type efflux system in Borrelia burgdorferi is involved in virulence and resistance to antimicrobial compounds.

Borrelia burgdorferi is remarkable for its ability to thrive in widely different environments due to its ability to infect various organisms. In comparison to enteric Gram-negative bacteria, these spirochetes have only a few transmembrane proteins some of which are thought to play a role in solute and nutrient uptake and excretion of toxic substances. Here, we have identified an outer membrane protein, BesC, which is part of a putative export system comprising the components BesA, BesB and BesC.

Silver- and Coomassie-staining protocols: detection limits and compatibility with ESI MS.

Staining protocols for PAGE have to be sensitive and should not impair further MS analysis of selected samples. In this study, the MS compatibility of different silver- and Coomassie-staining protocols with a nano-LC-MS/MS system was systematically elucidated. Altogether, 13 different silver-staining, 1 imidazole-staining and 2 Coomassie-staining protocols were used and compared to each other for their achieved sequence coverage and their detection sensitivity.

Ruthenium (II) tris-bathophenanthroline disulfonate is well suitable for Tris-Glycine PAGE but not for Bis-Tris gels.

Pre-cast bis(2-hydroxyethyl)iminotris(hydroxymethyl)methane (Bis-Tris) gels have proven to be very suitable for pre-fractionation for LC-MS/MS analysis due to high reliability and long stability. To visualize proteins within gels fluorescence dyes proved to be a good tradeoff between sensitivity and MS-compatibility. The custom-made ruthenium dye represents a low-cost alternative regarding fluorescence-based protein visualization with high sensitivity.

Elimination of channel-forming activity by insertional inactivation of the p66 gene in Borrelia burgdorferi.

P66 is a chromosomally encoded 66-kDa integral outer membrane protein of the Lyme disease agent Borrelia burgdorferi exhibiting channel-forming activity. Herein, we inactivated and subsequently complemented the p66 gene in the B31-A (WT) strain. The P66 protein was also inactivated in two other channel-forming protein mutant strains, P13-18 (Deltap13) and Deltabba01, and then compared with the channel-forming activities of wild-type and various p66 mutant strains.

The BBA01 protein, a member of paralog family 48 from Borrelia burgdorferi, is potentially interchangeable with the channel-forming protein P13.

The Borrelia burgdorferi genome exhibits redundancy, with many plasmid-carried genes belonging to paralogous gene families. It has been suggested that certain paralogs may be necessary in various environments and that they are differentially expressed in response to different conditions. The chromosomally located p13 gene which codes for a channel-forming protein belongs to paralog family 48, which consists of eight additional genes.

Site-directed mutagenesis of the greasy slide aromatic residues within the LamB (maltoporin) channel of Escherichia coli: effect on ion and maltopentaose transport.

The 3D-structure of the maltooligosaccharide-specific LamB-channel of Escherichia coli (also called maltoporin) is known from X-ray crystallography. The 3D structure suggests that a number of aromatic residues (Y6, Y41, W74, F229, W358 and W420) within the channel lumen are involved in carbohydrate and ion transport. All aromatic residues were replaced by alanine-scanning mutagenesis.