[Membrane glycoproteins and platelet protein glycosylation in chronic myeloid leukemia]

SDS-polyacrylamide gel electrophoresis of solubilized whole platelets and isolated platelet membranes from patients with chronic myeloid leukemia (CML) as compared to the normal platelet-Schiff-stained glycoproteins (GP) (noted GP I, II, III of app. MW 155, 130 and 100.10(3) daltons, respectively), showed the following modifications: the decrease of GP I; the presence of the GP II and GP IIx doublet; the moderate and variable decrease of the GP III; the increase of the platelet glycolipid. No significant differences were detectable on the polypeptide patterns from CML platelets in respect to the normal 20-25 protein constituents. Using a radio-isotopic method it has been measured as an elevated catalytic transfer of the galactosyl and N-acetylgalactosaminyl residues from nucléotide 14C sugar derivatives onto the endogenous acceptors of platelets from CML. The results obtained suggested that CML platelets with recognized abnormal functions, have modifications at the level of the macromolecular surface glycoprotein constituents and/or changes of the glycoconjugates reactive structures involved in the devopment of the periodic acid-Schiff reaction as also in the transfer reaction of the sugar residues.