THE ROLE OF AMINO GROUPS IN THE BIOLOGICAL AND ANTIGENIC ACTIVITIES OF CLOSTRIDIUM PERFRINGENS TYPE A ENTEROTOXIN

Clostridium perfingens type A enterotoxin has 8 amino groups which are readily reactive with 2, 4, 6-trinitrobenzene sulfonic acid (TNBS) in 20 mM phosphate buffer, pH 6.8, and 10 amino groups which react with TNBS only after denaturation with 6.5 M guanidine · HCl ≤ 25°C. The one sulfhydryl group of enterotoxin is not reactive with 5,5'-dithiobis-(2-nitrobenzoic acid) (DTNB) in the native molecule (phosphate buffer, pH 6.8), but is reactive in the presence of 0.2% sodium dodecyl sulfate at 25°C.
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