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Sialyl-glycopeptides containing an 0-glycosidically linked tetrasaccharide chain were obtained from the urine of a patient suffering from mucolipidosis I. Isolation of these compounds was achieved by gel filtration, ion-exchange chromatography and preparative paper chromatography. Their structures were determined by a combination of carbohydrate and amino acid analysis, dansylation, periodate oxidation, methylation studies, enzymatic hydrolysis and 'H-NMR spectroscopy, to be as follows:wherein R = peptide linked through -Thr-, -Ser-, -Ser-Thr-or -Thr-Ser-.The finding of these glycopeptides in urine shows that mucolipidosis I is characterized by a general "glycoproteinspecific" sialidase deficiency. The possibility of the existence of a human endo-a-N-acetylgalactosaminidase is discussed.Mucolipidosis I (MLP-I, one of the forms of sialidosis) is an inherited metabolic disease characterized clinically by the presence of a cherry-red spot on the fundus, by elective overload of the Kupffer cells and by a variety of neurological syndroms. Chemical studies of this disease showed accumulation of abnormal amounts of sialic-acid-containing compounds in fibroblasts and leukocytes of the patients, due to a deficiency of sialidase activity in these cells. By consequence, an enhanced excretion of sialic-acid-containing oligosaccharides was observed in the urine of MLP-I patients; these oligosaccharides originate from the impaired catabolism of N-glycosidic glycoprotein carbohydrate chains [I -41.However, the sialidase deficiency in MLP-I does not only affect the catabolism of the N-glycosidic type of glycoprotein oligosaccharides but, as previously reported by us [5] and others [6], also the excretion of the 0-glycosidic type of glycoprotein carbohydrates is found increased about tenfold in MLP-I urine, as compared to normal. Structural studies on the excreted sialic-acid-containing compounds of the 0-glycosidic type have been scarce until now; however, the occurrence of a Abbreviations. MLP-I, mucolipidosis I; 'H-NMR, proton nuclear magnetic resonance; NeuAc, N-acetylneuraminic acid ; Gal, galactose; CalNAc, N-acetylgalactosamine; 2,4,6-Me3-Gal-ol, 2,4,6-tri-Ornethyl-l,3,5-tri-O-acetyl-galactitol; 2,3,4,6-Me4-Gal-ol, 2,3,4,6-tetra-O-methyl-1,5-di-O-acetyl-galactitol; 4-Me-GalNAc(Me)-ol, 2-deoxy -2 -N -methylace tamido -4-mono -0 -methyl -1,3,5,6 -te tra-0 -acetyl-galactitol; 4,6-Me2-GalNAc(Me)-01, 2-deoxy-2-N-methylacetamido-4,6-di-O-methyl-l,3,5-tri-O-acetyl-galactitol.Enzymes. a-Neuraminidase (EC 3.2.1.18); P-D-galactosidase (EC 3.2.1.23).glyco-aminoacid constituted of NeuAc, GalNAc and Ser has been reported [7].The present work describes the structure determination of some sialyl-glycopeptides of the 0-glycosidic type isolated from the urine of a patient suffering from MLP-I. The results provide further insight into the biochemical consequences of the enzyme deficiency. A preliminary account of the outcome of the structural studies has been presented [S]. MATERIALS AND METHODS MaterialsUrine of a patient (P.P.) with MLP-...

Lyophilized pancreas and pancreatic extracts are widely used in therapy of pancreatic exocrine function deficiencies. Among the measures for quality of the extracts, assay for lipolytic activity appears to be one of the best. However, assay precision is poor, because the specificity and mode of action of lipase requires careful optimization of the assay parameters, especially substrate and measurement conditions. In the method proposed here, substrate quality is improved by the use of sodium desoxycholate and a high-speed stirrer for more reproducible emulsions. Fatty acids are assayed by a titrimetric method, using an electronically monitored pH meter. A comparative statistical study of the U.S. Pharmacopeia method, the International Pharmaceutical Federation (FIP) method, and a modified FIP method showed the latter to have improved accuracy and reproducibility.