title: Purification and some properties of a Vero toxin from a human strain of Escherichia coli that is immunologically related to Shiga-like toxin II (VT2).
abstract: A cytotoxin to Vero cells (Vero toxin), which was immunologically related to Shiga-like toxin II (SLT-II) (or VT2), was purified from a stain of Escherichia coli isolated from a patient with hemolytic uremic syndrome. The toxin was active on Vero cells but much less active on HeLa cells, a property similar to that of the recently identified SLT-II variant from E. coli strains that caused edema disease of swine. Thus the toxin purified in this report was tentatively named Shiga-like toxin II variant (Vero toxin 2 variant). The purification procedures consisted of ammonium sulfate fractionation, DEAE-Sepharose CL-6B column chromatography, chromatofocusing column chromatography, and repeated high performance liquid chromatography (HPLC) on TSK-gel G-2000SW column and on TSK-gel DEAE-5PW columns. About 90 micrograms of purified toxin was obtained from 451 of the culture supernatant with a yield of about 16%. The purified toxin consisted of A and B subunits of molecular sizes similar to those of SLT-II (VT2). The isoelectric point of the purified toxin was 6.1, which was different from that of SLT-II (VT2) (pI = 4.1). In an Ouchterlony double gel diffusion test, purified toxin and SLT-II (VT2) formed precipitin lines with spur formation against anti-purified toxin and anti-SLT-II (anti-VT2), respectively. The purified toxin was cytotoxic to Vero cells, about 6 pg of the toxin killing 50% of the Vero cells, and showed lethal toxicity to mice when injected intraperitoneally, the LD50 being about 2.7 ng per mouse.
authors.affiliation: Department of Bacterial Infection, Institute of Medical Science, University of Tokyo, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Oku
authors.forename: T
authors.initials: T
authors.lastname: Yutsudo
authors.forename: T
authors.initials: T
authors.lastname: Hirayama
authors.forename: A D
authors.initials: AD
authors.lastname: O'Brien
authors.forename: Y
authors.initials: Y
authors.lastname: Takeda
mesh_terms: D001427:Bacterial Toxins / Q000276:immunology / Q000302:isolation & purification* / Q000633:toxicity; D004926:Escherichia coli / Q000032:analysis*; D006801:Humans; D022622:Shiga Toxin 1; D022641:Shiga Toxin 2
chemical_list: D001427:Bacterial Toxins; D022622:Shiga Toxin 1; D022641:Shiga Toxin 2