Outer Membrane Protein-A Bacterial Recombinant
The recombinant form was found to be undistinguishable from the wild type when examined by SDS-PAGE and gel filtration chromatography yielding a 48 kDa monomeric protein. The immunological similarity of the protein samples was demonstrated by employing polyclonal and monoclonal antibodies in ELISA and Western Blot techniques. All forms of A-protein were found to activate the secretion of tumour necrosis factor alpha from murine macrophage. For ref see Maurice et al. (1999) Protein Expression and Purification 16, 396-404.
The OmpA is purified by proprietary chromatographic techniques.
Accession
Amino acid sequence
The sequence of the first five N-terminal amino acids was determined and was found to be Met-Asp-Val-Val-Ile-Ser.
Biological Activity
The interaction of bacterial and recombinant A-layer protein with murine macrophages was directed at determining the effect of A-protein on intracellular events that occur in primed macrophages. This was accomplished by measuring the cytotoxic product produced by peritoneal macrophages when exposed to A-protein coated latex beads. Thioglycolate elicited macrophages exhibited a low level of activation (18% cytotoxicity) that was significantly increased (48% cytotoxicity) in the presence of latex beads. Coating of the latex beads with each of the three A-protein products resulted in an increase of cytoxicity (mean +/- SEM) from 48% to 91%.
Physical Appearance
Sterile Filtered White lyophilized (freeze-dried) powder.
Purity
Greater than 98.0% as determined by:
(a) Analysis by SEC-HPLC.
(b) Analysis by SDS-PAGE.
Solubility
It is recommended to reconstitute the lyophilized OmpA in sterile 0.4% NaHCO3.
Source
Stability
Lyophilized Bacterial Outer Membrane Protein-A although stable at room temperature for 3 weeks, should be stored desiccated below -18oC. Upon C between 2-7 days and for future usereconstitution OmpA should be stored at 4 below -18oC. For long term storage it is recommended to add a carrier protein (0.1% HSA or BSA).
Please avoid freeze-thaw cycles.
Synonyms
Outer Membrane Protein-A, OmpA.
