Staphylococcal Enterotoxin A (SEA)

Publisher Summary Staphylococcal enterotoxin A (SEA) stimulates the production of interferon of the immune type in both splenic and peripheral lymphocytes. This chapter describes the method of purification of (SEA). Enterotoxin A is a simple protein composed of a single polypeptide chain containing one disulfide bridge and no free sulfhydryl groups. Purified SEA is homogeneous in the analytical ultracentrifuge. It gives a single line in disc electrophoresis at pH 4.3 and in sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis. Some of its chemical and physical properties are presented. It is noted that the isoelectric point obtained by isoelectric focusing is given only for its major component. In common with SEB and SEC, enterotoxin A always displays a paucidispersity in isoelectric focusing demonstrable both in polyacrylamide gels and in sucrose-stabilized ampholine pH gradient. Enterotoxin A is extremely toxic to man. The toxin is preserved as a lyophilized powder, which should never be weighed out. It should be reconstituted with the appropriate solvent through the septum sealing the vial.