Investigation of the role of the disulphide bond in the activity and structure of staphylococcal enterotoxin C1. Mol Microbiol 1994 Sep;13(5):897-909
Date
09/01/1994Pubmed ID
7815947DOI
10.1111/j.1365-2958.1994.tb00481.xScopus ID
2-s2.0-0028104097 (requires institutional sign-in at Scopus site) 82 CitationsAbstract
The goal of this study was to investigate the role of the disulphide bond of staphylococcal enterotoxin C1 (SEC1) in the structure and activity of the toxin. Mutants unable to form a disulphide bond were generated by substituting alanine or serine for cysteine at positions 93 and/or 110. Although we did not directly investigate the residues between the disulphide linkage, tryptic lability showed that significant native structure in the cystine loop is preserved in the absence of covalent bonding between residues 93 and 110. Since no correlation was observed between the behaviour of these mutants with regard to toxin stability, emesis and T cell proliferation we conclude that SEC1-induced emesis and T cell proliferation are dependent on separate regions of the molecule. The disulphide bond itself is not an absolute requirement for either activity. However, conformation within or adjacent to the loop is important for emesis. Although mutants with alanine substitutions were not emetic, those with serine substitutions retained this activity, suggesting that the disulphide linkage stabilizes a crucial conformation but can be replaced by residues which hydrogen bond.
Author List
Hovde CJ, Marr JC, Hoffmann ML, Hackett SP, Chi YI, Crum KK, Stevens DL, Stauffacher CV, Bohach GAAuthor
Young-In Chi PhD Assistant Professor in the Surgery department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
Amino Acid SequenceAnimals
Cystine
Cytokines
Enterotoxins
Humans
Hydrogen Bonding
Lymphocyte Activation
Macaca nemestrina
Models, Molecular
Molecular Sequence Data
Protein Conformation
Rabbits
Shock, Septic
Structure-Activity Relationship
T-Lymphocytes
Trypsin
Vomiting
