Phenyl beta-D-Galactopyranoside as an Acceptor Substrate for the Blood-Group H Gene-Associated Guanosine Diphosphate L-Fucose:beta-D-Galactosyl alpha-2-L-Fucosyltransferase

• Phenyl β-d-galactopyranoside was found to be an efficient acceptor of l-[14C]fucose when guanosine diphosphate l-[14C]fucose was used as the donor substrate and human serum, submaxillary glands or stomach mucosa were the sources of l-fucosyltransferase. The enzyme utilising phenyl β-D-galactoside was present in the serum of donors of all ABO blood-groups examined, except those of the rare Oh (Bombay) and Bh phenotypes, but was clearly demonstrable in submaxillary gland preparations only when the glands came from individuals who were secretors of ABH blood-group substances. This distribution coincides with that previously established for the blood-group H gene-specified α-2-l-fucosyltransferase. The product of l-[14C]fucosyl transfer to phenyl β-d-galactoside is separable from the other radioactive components in the enzyme digest by chromatography for 4 h in ethyl acetate/pyridine/water (10/4/3, by vol.); it was characterised as phenyl 2-O-(α-l-[14C]fucopyranosyl)β-d-galactopyranoside by (a) the liberation of l-[14C]fucose by a specific α-2-l-fucosidase, (b) its resistance to degradation by alkali and (c) the identification of tritiated glycerol as a product of periodate oxidation after a 3H label had been introduced into the galactosyl moiety. The use of phenyl β-d-galactopyranoside as acceptor substrate thus provides a simple and relatively rapid method for the assay of the blood-group H gene-specified α-2-l-fucosyltransferase.

Subject headings

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Hematologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Hematology (hsv//eng)

Publication and Content Type

art (subject category)

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