Lymphocytes, monocytes, neutrophilic granulocytes and platelets were each separated to greater than 95% purity from six normal subjects, three patients with Gaucher's disease, two heterozygotes for Gaucher's disease, and one patient with Fabry's disease. Activities of the following acid hydrolases were determined: "acid" (pH 4.0) beta-glucosidase, pH 5.0 beta-glucosidase, alpha-galactosidase, a...

The human adenocarcinoma cell line Caco-2 was used for studies on the biosynthesis and transport of lysosomal acid alpha-glucosidase in polarized epithelial cells. Metabolic labelling revealed that in Caco-2 cells alpha-glucosidase is synthesized as a precursor form of 110 x 10(3) Mr. This form is converted into a precursor of slightly higher Mr (112 x 10(3)) by the addition of complex oligosac...

Membrane associated alpha-glucosidase activity was investigated in a methanogenic bioreactor (MR) and a biosulfidogenic bioreactor (SR). Temperature and pH optima studies showed temperature optima of 50 degrees C and pH optima of 8.0 for the alpha-glucosidases from both the MR and SR. Sulfide (at a concentration of 150 mg l(-1)) resulted in the complete loss of all alpha-glucosidase activity in...

From January 1985 to January 1990, measurements of acid alpha-D-glucosidase activity in amniocytes or chorionic villus samplings were done for 24 pregnant mothers who were carriers of Pompe's disease. 6 women had two subsequent pregnancies. Amniotic fluid was obtained by transabdominal amniocentesis performed on 10 of them, while chorionic villus samplings were obtained in the other 20. The res...

We are investigating the molecular mechanisms involved in the localization of lysosomal enzymes in Dictyostelium discoideum, an organism that lacks any detectable mannose-6-phosphate receptors. The lysosomal enzymes alpha-mannosidase and beta-glucosidase are both initially synthesized as precursor polypeptides that are proteolytically processed to mature forms and deposited in lysosomes. Time c...

1. The behaviour of rat liver alpha-glucosidases on dextran gel (Sephadex G-100) columns was studied. A ;retardation' of an acid alpha-glucosidase activity was observed. This activity was identified as lysosome alpha-(1-->4)-glucosidase. A single gel-filtration step resulted in a 700-fold purification of the enzyme. The same technique was also used to purify the acid alpha-glucosidase of human ...

1. The pH-activity relationship of invertase has been studied in vivo and in vitro under identical external environmental conditions. 2. The effect of changing (H(+)) upon the sucroclastic activity of living cells of S. cerevisiae and of invertase solutions obtained therefrom has been found, within experimental error, to be identical. 3. The region of living yeast cells in which invertase exert...