Bacterial outer membrane protein analysis by electrophoresis and microchip technology

Abstract

Outer membrane proteins are indispensable components of bacterial cells and participate in several relevant functions of the microorganisms. Changes in the outer membrane protein composition might alter antibiotic sensitivity and pathogenicity. Furthermore, the effects of various factors on outer membrane protein expression, such as antibiotic treatment, mutation, changes in the environment, lipopolysaccharide modification and biofilm formation, have been analyzed. Traditionally, the outer membrane protein profile determination was performed by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Converting this technique to capillary electrophoresis format resulted in faster separation, lower sample consumption and automation. Coupling capillary electrophoresis with mass spectrometry enabled the fast identification of bacterial proteins, while immediate quantitative analysis permitted the determination of up- and downregulation of certain outer membrane proteins. Adapting capillary electrophoresis to microchip format ensured a further ten- to 100-fold decrease in separation time. Application of different separation techniques combined with various sensitive detector systems has ensured further opportunities in the field of high-throughput bacterial protein analysis. This review provides an overview using selected examples of outer membrane proteins and the development and application of the electrophoretic and microchip technologies for the analysis of these proteins.

Identification of Outer Membrane Proteins Altered in Response to UVC-Radiation in Vibrio parahaemolyticus and Vibrio alginolyticus

“…After the beginning of an adverse effect, such as irradiation, the synthetic of proteins are inhibited and cells division is interrupted. In parallel, the expression of several proteins increases; these are the so-called stress proteins [21]. [25].…”

Searching for Outer Membrane Proteins Typical of Serum-Sensitive and Serum-Resistant Phenotypes of Salmonella

“…Because OMPs are also surface virulence factors and have a significant role in pathobiology of Gram-negative bacteria and bacterial adaptation to environmental conditions, many authors have directed their investigations through the analysis of Salmonella OMP patterns using various molecular methods to investigate these antigens (see below). OMPs are of special interest to researchers as they can modify the susceptibility of bacteria to the bactericidal activity of serum (Alberti et al, 1993;Kustos et al, 2007).…”

Identification of outer membrane proteins of Vibrio parahaemolyticus and Vibrio alginolyticus altered in response to γ-irradiation or long-term starvation

“…Outer membrane proteins (OMPs) play a key role in adaptation to changes of external environments due to their location at the outermost area of the cell (Xu et al, 2005). It has been shown that when bacteria are transferred to a new environment, the synthesis of their OMPs changes (Kustos et al, 2007). In this way, Wu et al (2006) demonstrated that OmpW and OmpV are required for environmental salt regulation in Photobacterium damsela.…”