Almost all integral membrane proteins found in the outer membranes of Gram-negative bacteria belong to the transmembrane β-barrel family. These proteins are not only important for nutrient uptake and homeostasis, but are also involved in such processes as adhesion, protein secretion, biofilm formation, and virulence. As surface exposed molecules, outer membrane β-barrel proteins are also potent...

Tom40 is an integral protein of the mitochondrial outer membrane, which as the central component of the Translocase of the Outer Membrane (TOM) complex forms a channel for protein import. We characterize the diffusion properties of individual Tom40 molecules fused to the photoconvertable fluorescent protein Dendra2 with millisecond temporal resolution. By imaging individual Tom40 molecules in i...

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...

       The purpose of this study was to investigate the effect of additives, poly(ethylene glycol) (PEG) 1450, poloxamer 407, polyvinyl alcohol (PVA) and sodium chloride in order to improve physico-chemical characteristics, encapsulation efficiency and in vitro release of bovine serum albumin, form poly(D,L-lactic-co-glycolic acid) (PLGA) microparticles prepared by the w/o/w solvent evaporation...

Import of proteins into the mitochondrial matrix requires translocation across two membranes. Translocational intermediates of mitochondrial proteins, which span the outer and inner membrane simultaneously and thus suggest that translocation occurs in one step, have recently been described (Schleyer, M., and W. Neupert, 1985, Cell, 43:339-350). In this study we present evidence that distinct me...

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...