Substrate specificity and distribution of acid beta-galactosidase activities in seizure-susceptible and non-susceptible strains of mice.
The properties and distribution of beta-galactosidase were studied in the mouse brain using the artificial substrate methylumbelliferyl-beta-galactoside. Enzyme activities were compared between an audiogenic seizure-susceptible mouse strain (DBA/2) and three non-susceptible strains of mice (BALB/c, C3H/He and Swiss A2G). At all ages, DBA/2 mice have significantly lower beta-galactosidase activity compared with the three other mouse strains: this is attributed to the different alleles present at the Bgs locus. The low activity of beta-galactosidase is also evident when the natural substrate GMl-ganglioside is hydrolyzed. In contrast to this low GMl-ganglioside-beta-galactosidase activity, there is no difference in the activity of the second form of acid beta-galactosidase, galactosylceramidase, in DBA/2 mice at 7 and 14 days. However, at 21 and 28 days the activity is significantly lower in DBA/2 mice compared with the other strains of mice. These results on beta-galactosidase activity in the brain of seizure-susceptible and non-susceptible mice are discussed in relation to published levels of GMl-ganglioside and galactosylceramide present in the developing mouse brain.
D000161:Acoustic Stimulation; D000818:Animals; D004198:Disease Susceptibility; D005696:Galactosidases / Q000378:metabolism*; D005697:Galactosides; D005699:Galactosylceramides; D006923:Hymecromone / Q000031:analogs & derivatives; D007790:Lactosylceramides; D051379:Mice; D008805:Mice, Inbred A; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008811:Mice, Inbred DBA; D012640:Seizures / Q000201:enzymology*; D013045:Species Specificity; D013347:Subcellular Fractions / Q000201:enzymology; D013379:Substrate Specificity; D001616:beta-Galactosidase / Q000378:metabolism*
D005697:Galactosides; D005699:Galactosylceramides; D007790:Lactosylceramides; D006923:Hymecromone; C026845:4-methylumbelliferyl-galactopyranoside; D005696:Galactosidases; D001616:beta-Galactosidase