URINARY MUCOPROTEINS
FIRST REPORT. COMPARISON OF ISOLATION METHODS AND PARTIAL CHARACTERIZATION OF THE BIOCHEMICAL PROPERTIES
1971 Volume 62 Issue 6 Pages 431-438
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1971 Volume 62 Issue 6 Pages 431-438
Mucoproteins were isolated from the normal human urine, using a method of salting out with sodium chloride (Tamm-Horsfall method, 1952) and a method of absorption on benzoic acid (Anderson-Maclagan method, 1955). The biochemical properties of the urinary mucoproteins isolated by these two methods were investigated and compared with each other.
1) The substance isolated from the urine, regardless of the difference of the methods, are similarly proven to contain nearly all kinds of amino-acids which constitute the protein. The content of hexosamine in the mucoproteins is 5.9% by Tamm-Horsfall method and 5.1% by Anderson-Maclagan method.
2) The urinary mucoproteins show a maximum absorption of ultraviolet ray at 277mμ wavelength, and give a peculiar purple color reaction of maximum absorption at 520mμ wavelength with the diphenylamine reagent. This color reaction is suitably applied for quantitative determination of the urinary mucoproteins.
3) The urinary mucoproteins are separated into three fractions by the gel-filtration method. Fraction 1 consists of substances of molecular weight not less than 2×105, fraction 2 of substances of molecular weight approximately corresponding to that of bovin albumin, fraction 3 of substances of lower molecular weight including lysozyme molecules. But the proportional constitution of the fractions differs between the two isolation methods. The mucoproteins obtained by Tamm-Horsfall method are composed almost exclusively of fraction 1, whereas the ones isolated by Anderson-Maclagan method contains relatively larger amounts of fraction 2 and 3.
4) The correlation between the activity of the urinary lysozyme and the amount of fraction 3 contained in the urinary mucoproteins is demonstrated.
