Concentrated cell-free filtrates, prepared from a human strain of enterotoxigenic Escherichia coli, were subjected to isoelectric focusing, molecular sieve chromatography, and polyacrylamide disc gel electrophoresis. Isoelectric focusing in a pH 3 to 5 gradient resulted in two biologically active peaks, I and II, that electrofocused at pI 1.5 and 3.8, respectively. Molecular sieve chromatography of the major enterotoxic peak (II) at pH 3.8 indicated a molecular weight of 2,500. Polyacrylamide disc gel electrophoresis of ST revealed a single protein band containing enterotoxic activity.
|Original language||English (US)|
|Number of pages||3|
|Journal||Infection and Immunity|
|Publication status||Published - Jan 1 1980|
All Science Journal Classification (ASJC) codes