Human amniotic fluid alpha-L-fucosidase.

Publication/Presentation Date

11-1-1979

Abstract

The activity and properties of alpha-L-fucosidase in 24 samples of amniotic fluid have been investigated using the 4-methylumbelliferyl substrate. A wide range of fucosidase specific activity (0.20-1.45 nmol/min/mg protein) was found with an average value of 0.62 nmol/min/mg protein. Although no clear-cut correlation exist, there appear to be trends of decreasing fucosidase specific activity with increasing maternal age of donor and increasing gestational time. alpha-L-Fucosidase activity from four amniotic fluids was characterized kinetically and immunochemically and found not to differ in its properties due to maternal age of donor or gestational time. Isoelectric focusing revealed multiple forms between pH 5.0 and 6.8, with the majority of activity present between pH 5.0 and 6.0. The pH optimum is near pH 5.0 with a second optimum suggested at pH 6.2. The apparent Michaelis constant (Km) for the 4-methylumbelliferyl substrate is 0.05 +/- 0.01 mM. The enzyme is completely thermostable at 37 degrees C for at least 4 h but loses 95% of its activity after preincubation at 45 degrees C for 1 h. Double immunodiffusion and immunoprecipitation experiments using anti-liver alpha-L-fucosidase antibody suggest that the amniotic fluid alpha-L-fucosidase is antigenically similar, if not identical, to the human liver enzyme.

Volume

16

Issue

5

First Page

357

Last Page

363

ISSN

0009-9163

Disciplines

Medicine and Health Sciences

PubMedID

42498

Department(s)

Department of Medicine

Document Type

Article

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