STRUCTURES OF THE CARBOHYDRATE CHAINS OF THE MOLECULAR-FORMS OF ALPHA-1-ACID GLYCOPROTEIN FROM ASCITIC FLUID OF STOMACH-CANCER PATIENTS

The immunochemically pure alpha(i)-acid glycoprotein (aAGP) from ascit ic fluid of patients with stomach cancer was separated by chromatograp hy on Con A-Sepharose into Con A-nonbound (aAGP-1, 43, 5 kDa, 70%) and Con A-bound (aAGP-2, 41,5 kDa, 24% and aAGP-3, 40,0 kDa, 5%) forms, d iffering in the monosaccharide composition. Comparative study of struc tures of their N-carbohydrate chains with the aid of the HPLC of fluor escence-labelled oligosaccharides showed that the molecular forms diff er by the ratio of the di-, tri-, and tetraantennary carbohydrate N-ch ains of a complex type. The molecular forms of aAGP differ from nAGP b y amounts of Le(x)-fragments and agalacto-oligosaccharides.