title: Physiochemical properties of a heat-stable enterotoxin produced by Escherichia coli of human origin.
abstract: 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.
mesh_terms: D001427:Bacterial Toxins / Q000032:analysis*; D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D004768:Enterotoxins / Q000032:analysis*; D004926:Escherichia coli / Q000032:analysis*; D006358:Hot Temperature; D006801:Humans; D007526:Isoelectric Point; D008970:Molecular Weight
chemical_list: D001427:Bacterial Toxins; D004768:Enterotoxins