Oligosaccharides sialidosis urine

Fig. 27.—Structure of Oligosaccharides Isolated from Sialidosis Urine (continued on pp. 192 and 93).,7,-,7e...

Figure 4.2.2 depicts the urinary oligosaccharide patterns of sialidosis (a-neur-aminidase deficiency), GM1 gangliosidosis and mucopolysaccharidosis type IVB (/3-galaclosidase deficiency) compared to a normal urine and standards of raffinose, lactose and glucose. In patients with sialidosis, a densely staining band close to the... 

Compound 22 is a mono-antennary, lower-branch, sialo oligosaccharide, isolated in admixture with 21 from the urine of a patient with sialidosis. The 500-MHz, H-n.m.r. spectrum of the mixture is given in Fig. 20 the set of lower-intensity signals belongs to 22. The n.m.r. parameters for 22 are summarized in Table IX. For the interpretation of the n.m.r. spectrum, comparison with the spectra of 18 and 21 is appropriate. 

Compounds 36 and 37 are diantennary, monosialo oligosaccharides, each containing an a-(2- 3)-linked NeuAc group. They were obtained in a mixture (together with a small amount of 27) from the urine of a patient with sialidosis.52,72 The 500-MHz, H-n.m.r. spectrum of this mixture, containing 36 and 37 in the ratio of 3 1, is presented in Fig. 28. The n.m.r. data for both oligosaccharides are given in Table XI. 

By the theoretical addition of the structural sequences [(51) and (52)] to the oligosaccharides isolated from human urine from mannosidosis, fucosidosis, or sialidosis patients, numerous structures of L-asparaginyl glycans can be proposed. " It is postulated that these structures, which have not yet been characterized, pre-exist in glycans of human glycoproteins, probably in the cytoplasm and/or the cell membrane, and that they are the products of the action of endo-/3-D-2-acetamido-2-deoxy-glucanases and accumulate in the cells and then in the urine. 

Strecker, G., Peers, M.C., Michalski, J.C., Hondi-Assah, T., Fousnet, B., Spik, G., Montreuil, J., Farriaux, J.P., Maroteaux, P. Durand, P. (1977) Structure of Nine Sialyl-Oligosaccharides Accumulated in Urine of Eleven Patients with Three Different Types of Sialidosis , European Journal of Biochemistry, 75, 391-403... 

There is, however, a remarkable knowledge of the detailed chemical structures of the sialic acid-containing oligosaccharides excreted in the patient s urine. Thus, SiRECKERe/a/. (1977), MiCHALSKie/a/. (1977) and Strecker(1980) characterized a total of 20 different sialyloligosaccharides found in the urine of both severe and mild cases of sialidosis. When compared to the normal, the excretion of these compounds was increased about 80- to 800-fold. The complete structures of the 10 major sialyloligosaccharides excreted by a patient with the severe form are shown... 

---