Premium
Acid β‐mannosidase of human plasma: Influence of age and sex on enzyme activity
Author(s) -
Cooper A.,
Hatton C.,
Sardharwalla I. B.
Publication year - 1987
Publication title -
journal of inherited metabolic disease
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.462
H-Index - 102
eISSN - 1573-2665
pISSN - 0141-8955
DOI - 10.1007/bf01800067
Subject(s) - mannosidase , enzyme assay , endocrinology , enzyme , medicine , heterozygote advantage , human plasma , chemistry , specific activity , biology , biochemistry , genotype , chromatography , gene
Summary Optimum conditions for assay of human plasma β‐mannosidase activity were determined. Maximum activity was observed at pH 3.0–3.4, the apparent K m was 0.9 mmol L −1 and enzymatic hydrolysis was linear for at least 60 min. Assays were performed on plasma from two siblings with the recently described condition β‐mannosidosis and their parents and controls. Both β‐mannosidosis patients showed a marked deficiency of β‐mannosidase activity. Control samples showed no variation between sexes ( p >0.05) but enzyme activity varied significantly with age ( p <0.05). Highest activity was observed in the 0–1 year age group, activity then decreasing to adulthood, Both mother and father of the affected individuals showed reduced activity (34% and 53%, respectively) compared to age‐matched controls. This suggests that heterozygote detection in this condition is possible using plasma, provided the variation of activity with age is taken into consideration.