Staphylococcal enterotoxins (SEs) are emetic toxins that cause the intoxication staphylococcal food poisoning syndrome. Based on common immunological properties and some amino acid sequence identity, the SEs belong to a larger family of bacterial toxins, referred to as superantigens, that includes toxic shock syndrome toxin and streptococcal pyrogenic exotoxins. My long-term goals are to elucidate (i) the relationship between structure and activity for SE type A (SEA) and (ii) SEA's mechanism of action at the molecular level. The short-term goals (part of this proposal) are to (i) construct a map of SEA that defines peptide domains and individual amino acid residues that are and are not required for emesis and SEA's immunological activities and (ii) solve the structure of SEA by x-ray diffraction analysis of crystals. Detailed structure-activity information is necessary for elucidation of the molecular mechanism for SEA's biological activities which have applications for immune system biology and neurological-hormonal interactions.
