The use of tears for diagnosis of GM1 gangliosidosis.
The properties of beta-galactosidase of tears were investigated and the standard assay system was accomplished. The pH optimum was 4.2. The enzyme had a KM of 8.3 X 10(-4) M. The activity was stimulated by chloride ions and slightly stabilized by bovine serum albumin. The activities of normal individuals were 205 +/- 80 (S.D.) nmol/h/ml. The activity in the tears of the patient with GM1 gangliosidosis decreased to about 20% of normal control and this disease could be diagnosed by the assay of beta-galactosidase in tears.
D000293:Adolescent; D000328:Adult; D002712:Chlorides / Q000494:pharmacology; D004796:Clinical Enzyme Tests; D004355:Drug Stability; D005260:Female; D005696:Galactosidases / Q000378:metabolism*; D005733:Gangliosidoses / Q000175:diagnosis*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008297:Male; D012710:Serum Albumin, Bovine / Q000494:pharmacology; D013666:Tears / Q000201:enzymology*; D013997:Time Factors; D001616:beta-Galactosidase / Q000378:metabolism*
D002712:Chlorides; D012710:Serum Albumin, Bovine; D005696:Galactosidases; D001616:beta-Galactosidase