ABSTRACT
Chondroitin sulfate (CS) is a glycosaminoglycan consisting of repeating uronic acid, N-acetylgalactosamine sulfate disaccharide units [-UroA(beta1,3)-GalNAcS(beta1,4)]n. Chondroitin sulfate type A (CSA) contains glucuronic acid, and 90% of the GalNAc residues are sulfated at the 4-position with 10% at the 6-position. Chondroitin sulfate type C (CSC) contains glucuronic acid, and 90% of the GalNAc residues are sulfated at the 6-position with 10% sulfated at the 4-position. These molecules are fragile due to their high degree of sulfation and are challenging to analyze as a result. This work presents the first evidence that tandem mass spectrometry can be used for the determination of a CS oligosaccharide sequence with respect to the positions of GalNAc sulfation. Using this technique, it is possible to analyze individual components from mixtures, saving much purification effort. Oligosaccharides produced from CSA and CSC are used in this work to demonstrate that CID MS/MS can be used to distinguish positional sulfation isomers. For charge states where charge equals the number of sulfates, abundant odd-numbered Bn and Yn ions are observed. The percent total ion abundances of these ions indicate the position of sulfation.
Subject(s)
Chondroitin Sulfates/analysis , Oligosaccharides/analysis , Carbohydrate Sequence , Molecular Sequence Data , Spectrometry, Mass, Electrospray IonizationABSTRACT
The case of a 53-year-old man with acute megakaryoblastic leukemia (M7) was studied. At time of diagnosis, the platelet count was 980 X 10(9)/L and abnormal platelet vacuoles were present. The vacuoles were periodic acid-Schiff (PAS) positive. Electron microscopic examination showed large aggregates of glycogen. Findings of qualitative platelet function studies were abnormal. The authors' study and review of the literature indicates that thrombocytosis with large platelet vacuoles accompanying a blast cell population suggests a diagnosis of M7 and indicates the need for appropriate confirmatory studies.
