The outer membranes from Treponema pallidum subsp. pallidum and Treponema vincentii were isolated by a novel method. Purified outer membranes from T. pallidum and T. vincentii following sucrose gradient centrifugation banded at 7 and 31% (wt/wt) sucrose, respectively. Freeze fracture electron microscopy of purified membrane vesicles from T. pallidum and T. vincentii revealed an extremely low de...

Mycobacteria have low-permeability outer membranes that render them resistant to most antibiotics. Hydrophilic nutrients can enter by way of transmembrane-channel proteins called porins. An x-ray analysis of the main porin from Mycobacterium smegmatis, MspA, revealed a homooctameric goblet-like conformation with a single central channel. This is the first structure of a mycobacterial outer-memb...

Voltage-dependent anion-selective channel protein 1 (VDAC1, accession number: NP_003365.1) encodes for a protein product length of 283. VDAC1 regulates the flux of mostly anionic metabolites through the outer mitochondrial membrane, which is highly permeable to small molecules. VDAC is the most abundant protein in the outer membrane. Changes in membrane potentials can switch VDAC between open o...

Background: Outer inflammatory protein A (OipA) is one of the important adhesins of H. pylori and a valuable candidate for vaccine development. Its gene is under "on-off" switch status which correlates with OipA protein expression. Objectives: We aimed to obtain a recombinant OipA clone (with "on" status) from an Iranian clinical isolate. Materials and Methods: A clinical H. pylori-isolate demo...

Bovine rod outer segment (ROS) preparations contain a major 58 kDa protein doublet that was identified by immunoblot as tubulin. Quantification by gel densitometry showed that the total amount of tubulin was 5- to 10-fold higher than that attributable to the rod axoneme, suggesting additional role(s) for tubulin in photoreceptor cells. Approximately 20% of this nonaxonemal tubulin (15% of total...

P1 outer membrane proteins from Haemophilus influenzae type b are heterogeneous antigenically and with respect to apparent molecular weight in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. For determination of the molecular basis for the differences in the P1 proteins, the genes for the P1 proteins from strain 1613, representative of outer membrane protein subtype 3L, and strain 83...

The outer membrane of Gram-negative bacteria is an essential structure involved in nutrient uptake, protection against harmful substances, and cell growth. Different proteins keep the outer membrane from blebbing out by simultaneously interacting with it and with the cell wall. These proteins have been mainly studied in enterobacteria, where OmpA and the Braun and Pal lipoproteins stabilize the...