title: The separation and characterization of the methylumbelliferyl beta-galactosidases of human liver.
abstract: 1. A previously uncharacterized form of human liver acid beta-galactosidase (EC 3.2.1.23), possibly a dimer of molecular weight 160 000, was resolved by gel filtration. It has the same ability to hydrolyse GM1 ganglioside as the two other acid beta-galactosidase forms. 2. The low-molecular-weight forms of acid beta-galactosidase undergo salt-dependent aggregation. 3. The high-molecular-weight component may consist of the low-molecular-weight forms bound to membrane fragments. It can be converted completely into a mixture of these forms. 4. The neutral beta-galactosidase activity can be resolved into two forms by DEAE-cellulose chromatography. They differ in their response to Cl-ions. 5. A new nomenclature is suggested for the six beta-galactosidases so far found in human liver. 6. The enzymic constituents of the beta-galactosidase bands resolved by electrophoresis were re-examined. The A band contains three components. A two-dimensional electrophoretic procedure for resolving the A band is described. 7. The effect of neuraminidase treatment on the behaviour of beta-galactosidases in various separation systems is examined.
mesh_terms: D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D004592:Electrophoresis, Starch Gel; D005696:Galactosidases / Q000302:isolation & purification*; D006801:Humans; D006923:Hymecromone; D007525:Isoelectric Focusing; D007527:Isoenzymes / Q000302:isolation & purification; D008099:Liver / Q000201:enzymology*; D009439:Neuraminidase / Q000494:pharmacology
chemical_list: D007527:Isoenzymes; D006923:Hymecromone; D005696:Galactosidases; D009439:Neuraminidase