Heterogeneity in human acid beta-glucosidase revealed by cellulose-acetate electrophoresis.
Cellulose-acetate gel electrophoresis, a technique commonly used for the separation of human acid hydrolases, was applied to study heterogeneity in acid beta-glucosidase (EC 3.2.1.45). With this technique, three forms of beta-glucosidase were distinguishable in extracts of several tissues. The most anodic beta-glucosidase activity (band 3) represents the broad-specificity beta-glucosidase that is not deficient in Gaucher disease and is not inhibited by conduritol B-epoxide (CBE). The beta-glucosidase activity was deficient in Gaucher disease. A third beta-glucosidase activity with an intermediate mobility (band 2) was also inhibited by CBE and deficient in Gaucher disease. Band 1 and band 2 beta-glucosidase thus represent different forms of glucocerebrosidase. By adding phosphatidylserine and sphingolipid activator protein (SAP-2), monomeric glucocerebrosidase could be completely converted into a form that comigrated with band 2 beta-glucosidase of tissue extracts. The addition of phosphatidylserine only also resulted in a changed mobility of the monomeric enzyme, but the migration in this case differed from that of band 2 beta-glucosidase of tissue extracts. The electrophoretic profile of beta-glucosidase activity of tissue extracts changed upon ethanol/chloroform extraction: the two glucocerebrosidase forms were converted into a band with a mobility identical to that of band 1 beta-glucosidase. Our findings indicate that the interaction of glucocerebrosidase with phospholipid and SAP-2 has major effects on the mobility of the enzyme in the cellulose-acetate gel electrophoresis system. The findings with the cellulose-acetate gel electrophoretic system are discussed in relation to the heterogeneity in glucocerebrosidase observed with sucrose density gradient analysis, immunochemical methods and isoelectric focussing studies.
D004586:Electrophoresis; D004588:Electrophoresis, Cellulose Acetate; D005260:Female; D005347:Fibroblasts / Q000201:enzymology; D005776:Gaucher Disease / Q000201:enzymology*; D005959:Glucosidases / Q000032:analysis*; D005962:Glucosylceramidase / Q000032:analysis / Q000378:metabolism; D006023:Glycoproteins / Q000494:pharmacology; D006801:Humans; D007294:Inositol / Q000031:analogs & derivatives / Q000494:pharmacology; D007526:Isoelectric Point; D007668:Kidney / Q000201:enzymology; D007962:Leukocytes / Q000201:enzymology; D008099:Liver / Q000201:enzymology; D010718:Phosphatidylserines / Q000494:pharmacology; D010920:Placenta / Q000201:enzymology; D011247:Pregnancy; D049231:Saposins; D012997:Solvents; D049128:Sphingolipid Activator Proteins; D013154:Spleen / Q000201:enzymology; D013656:Taurocholic Acid / Q000494:pharmacology; D001617:beta-Glucosidase / Q000032:analysis* / Q000037:antagonists & inhibitors / Q000378:metabolism
D006023:Glycoproteins; C483345:PSAP protein, human; D010718:Phosphatidylserines; D049231:Saposins; D012997:Solvents; D049128:Sphingolipid Activator Proteins; D007294:Inositol; D013656:Taurocholic Acid; D005959:Glucosidases; D001617:beta-Glucosidase; D005962:Glucosylceramidase; C011423:conduritol epoxide