Title : Characterization of a posttranslational fucosylation in the growth factor domain of urinary plasminogen activator
Abstract :
A posttranslational modification site in natural and recombinant urinary-type plasminogen activators (urokinases; EC 3.4.21.31) has been localized to Thr-18 , in the growth factor domain of the molecule
This is the region of urinary plasminogen activator responsible for its specific receptor binding
An unusual carbohydrate-protein linkage, a single monosaccharide, fucose, covalently attached directly to threonine in the peptide , is described here
The glycan moiety and the site of modification have been identified with mass spectrometry and confirmed by carbohydrate com position analysis, Edman degradation, and one- and two-dimensional NMR studies
This type of modification is normally not detected without mass spectrometry because the fucose-threonine bond threonine bond is hydrolyzed under standard acidic conditions of the amino acid analysis and Edman sequencing
This modification may be widely found in other proteins