Charge heterogeneity of heat-labile enterotoxins from human enterotoxigenic Escherichia coli.
We purified heat-labile enterotoxins (LThs) from YT3, H-10407 and YT240 strains isolated from human diarrheal patients. These LThs were immunologically identical to each other. The molecular weights of their A and B subunits were also the same by means of SDS-polyacrylamide gel electrophoresis. However, the ionic charges of the molecular surfaces of these LThs were different as shown by polyacrylamide gel isoelectric focusing. Though the pI points of B subunits of the LThs were identical to each other, the pI points of A subunits were found to be different. These data suggest that the ionic charge differences among A subunits cause differences in holo LThs in their charge, and that there is heterogeneity among A subunits produced by strains of human enterotoxigenic Escherichia coli.
Tsuji
T
T
Department of Bacteriology and Serology, Research Institute for Microbial Diseases, Osaka University, Japan.
Yao
S K
SK
Joya
J E
JE
Honda
T
T
Miwatani
T
T
D001427:Bacterial Toxins / Q000032:analysis*; D003967:Diarrhea / Q000382:microbiology; D004591:Electrophoresis, Polyacrylamide Gel; D004768:Enterotoxins / Q000032:analysis*; D004926:Escherichia coli / Q000032:analysis* / Q000472:pathogenicity; D029968:Escherichia coli Proteins; D006801:Humans; D007525:Isoelectric Focusing
D001427:Bacterial Toxins; D004768:Enterotoxins; D029968:Escherichia coli Proteins; C034151:heat stable toxin (E coli)