Protein identification by peptide mass fingerprinting using matrix-assisted laser desorption ionization time of fight (MALDI-TOF) mass spectrometry (MS) can analyze unambiguously identity of the spots from a 2-dimensional electrophoresis (2-DE) gel. This study developed a technique for 2-DE of Salmonella enterica serovar Enteritidis (S. enteritidis) by improving the dissolution conditions by 2-DE using a pH 4 - 7 immobilized pH gradient (IPG) strip. This report examines the protein components from the patterns of the S. enteritidis protein. The most abundant protein displayed a great number of clusters within the pH 4.5 - 7 range with a molecular mass ranging from 35-80 kDa. Some of these spots were identified as metabolic related enzymes. The protein fraction was also analyzed using an immobilized pH gradient strip. Different proteins were identified on the spot according to the elongation factors. In addition, this study showed that the 2-DE analysis of S. enteritidis provides useful information regarding the S. enteritidis proteome, and this approach might provide a strategy for identifying bacterial proteins using a proteome technology.
Bacterial Proteins/analysis/*chemistry/isolation & purification ; Electrophoresis, Gel, Two-Dimensional ; Enzymes/chemistry/genetics/isolation & purification ; Molecular Weight ; Salmonella enteritidis/*chemistry/growth & development ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization

The immunologic reactivity of a lipopolysaccharide (LPS)-protein complex isolated from a potassium thiocyanate extract of a Pasteurella multocida (capsular type A and somatic type 3) strain was evaluated in mice. The LPS-protein complex provided 100% protection in mice against a challenge with the homologous strain. However, when the complex was fractionated into LPS and protein moieties by phenol-water treatment, both components lacked immunogenicity. The complex and extracted components were mitogenic for mouse B lymphocytes with the protein moiety the most active. Although immune serum against the LPS-protein complex protected mice against challenge thereby indicating a role for humoral immunity, the LPS-protein complex of P. multocida was also found to induce cell-mediated immunity. This cell-mediated immunity was demonstrated in mice immunized with the complex by: (1). mitogenic responses of T lymphocytes, (2). induction of delayed type hypersensitivity reaction in the hind footpads, and (3). enhanced resistance to challenge infection with Salmonella enteritidis.
Animals ; Antibodies, Bacterial/blood/immunology ; Bacterial Proteins/chemistry/*immunology ; Chemical Fractionation ; Hypersensitivity, Delayed ; Immune Sera/immunology ; Immunity, Cellular ; Immunization, Passive ; Lipopolysaccharides/chemistry/*immunology ; Lymphocyte Activation ; Mice ; Pasteurella Infections/immunology/*prevention & control ; Pasteurella multocida/*chemistry/immunology ; Salmonella Infections, Animal/immunology/prevention & control ; Salmonella enteritidis/growth & development/immunology ; Spleen/cytology/immunology/microbiology