The P Histo-Blood Group-Related Glycosphingolipid Sialosyl Galactosyl Globoside as a Preferred Binding Receptor for Uropathogenic Escherichia coli:  Isolation and Structural Characterization from Human Kidney

The P histo-blood group-related glycosphingolipid, sialosyl galactosyl globoside (SGG), has recently been implicated as a preferred binding receptor for uropathogenic Escherichia coli [Stapleton, A. E., Stroud, M. R., Hakomori, S., and Stamm, W. E. (1998) Infect. Immun. 66, 3856-3861]. We report here the purification and complete structural characterization of SGG from normal human kidney. Using metabolically [35S]-labeled E. coli as a probe, a monosialylated glycosphingolipid was isolated to homogeneity. The glycosphingolipid was purified by a combination of high-performance liquid chromatography and preparative high-performance thin-layer chromatography and its structure unambiguously elucidated by 1H NMR, electrospray ionization mass spectrometry, and methylation analysis. Its primary structure was shown to be identical to a previously characterized, developmentally regulated, globo-series glycolipid thought to be unique to human teratocarcinoma. The significance of this structure as a unique receptor in human kidney for uropathogenic E. coli and its role in the pathogenesis of urinary tract infections are discussed.