Fucose in 1H COSY spectra of plasma membrane fragments shed from human malignant colorectal cells

The methyl-methine cross peak of bound fucose has been assigned in the COSY spectrum of plasma membrane shed from human malignant colorectal cells. This cross peak (1.33-4.27 ppm), which is superimposed on the methyl-methine cross peak of threonine, was assigned following hydrolysis of the sample. Acid hydrolysis led to a 28 +/- 5% reduction in the intensity of the cross peak and the appearance of the alpha and beta forms of fucose. Chemical analysis confirmed the release of free fucose. Lactate anion, which was not perturbed by the hydrolysis, was used as an internal standard.