BIOCOLLOIDS OF URINE IN HEALTH AND IN CALCULOUS DISEASE. II. ELECTROPHORETIC AND BIOCHEMICAL STUDIES OF A MUCOPROTEIN INSOLUBLE IN MOLAR SODIUM CHLORIDE 1

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Abstract
Eight normal persons, 14 patients with renal calculi, and 2 with cutaneous ureterostomies were the subjects for this study. The biocolloids of dialyzed urine were recovered by ultra-filtration and the total residue was then extracted with [image] NaC1. The insoluble portion in NaC1 was analyzed for C, H, N, S and P. This residue was also analyzed for hexose, hexosamine, fucose and "sialic acid" content. Electrophoretic studies of the material were made at pH 8.6. The NaC1 insoluble residue was indistinguishable from the virus inhibitory mucoprotein of Tamm and Horsfall. The material was quantitatively much increased in the urine of patients with renal calculi, but was qualitatively similar to that recovered from normal subjects. Mucoprotein formed thixotropic gels in 0.1 [image] salt solutions at low temperatures. Freezing and lyophilization "denatured" mucoprotein as evidenced by marked reduction in solubility in 0.1 [image] buffer solutions. Treatment at pH 12.3 resulted in marked increase in the solubility in salt solutions with a loss of 2/3 of the hexosamine content. This soluble product was recovered from mucoprotein which was denatured by freezing or lyophilization, and it is suggested that recognition of this degradation product may be of value in studies of mucoprotein under conditions where denaturization may be unavoidable.