Guanidination and nitroguanidination of staphylococcal enterotoxin B.

Abstract

Guanidination of the free amino groups of staphylococcal enterotoxin B with 3,5-dimethyl-1-guanylpyrazole converted 31-32 of 33 epsilon-amino groups and 30% of the N-terminal residue. This product, although markedly reduced in solubility, suffered no gross change in conformation and retained full biological activity. A derivative prepared by reaction with O-methylisourea with only one lysyl residue unaltered lost most of its emetic activity. Nitroguanidination with 3,5-dimethyl-1-nitroguanylpyrazole converted up to 28 of the epsilon-amino groups and essentially all of the N-terminus. This material was greatly reduced in ability to produce emesis and like the O-methylisourea prepared guanidinated enterotoxin, gave only a line of partial identity in double diffusion. The loss of activity is attributed to unfolding and it is concluded that the free amino groups of enterotoxin B do not critically participate in either its antigenic determinants or its active center for emesis.

• Authors: L Spero, H M Jacoby, J E Dalidowicz, S J Silverman
• Journal: Biochimica et biophysica acta (Biochim Biophys Acta) Vol. 251 Issue 3 Pg. 345-56 (Dec 28 1971) ISSN: 0006-3002 [Print] Netherlands
• PMID: 11452875 (Publication Type: Comparative Study, Journal Article)

Chemical References

• Affinity Labels
• Amidines
• Enterotoxins
• Indicators and Reagents
• Methylurea Compounds
• Superantigens
• 3,5-dimethylpyrazole-1-carboxamidine
• O-methylisourea
• enterotoxin B, staphylococcal
• Glutamic Acid

Topics

• Affinity Labels
• Amidines
• Animals
• Enterotoxins (chemistry, toxicity)
• Glutamic Acid (chemistry)
• Immunodiffusion
• Indicators and Reagents
• Kinetics
• Lethal Dose 50
• Methylurea Compounds
• Staphylococcus aureus
• Superantigens (chemistry)