Immunochemically identical hydrophilic and amphiphilic forms of the bovine adrenomedullary dopamine beta-hydroxylase.
By means of a monospecific antibody, dopamine beta-hydroxylase was monitored immunoelectrophoretically in various extracts of chromaffin granules. Approximately one-third of the dopamine beta-hydroxylase present was located in the membrane fraction and could only be liberated with detergent. The dopamine beta-hydroxylases of the buffer and membrane fractions were antigenically identical, but differed in their amphiphilicity, as demonstrated by the change in precipitation patterns on removal of Triton X-100 from the gel, on charge-shift crossed immunoelectrophoresis and on crossed hydrophobic interaction immunoelectrophoresis with phenyl-Sepharose. Furthermore, immunoelectrophoretic analysis in the presence of Triton X-100 plus the cationic detergent cetyltrimethylammonium bromide indicates additional heterogeneity of the membrane-bound dopamine-beta-hydroxylase. By limited proteolysis with chymotrypsin and thermolysin the amphiphilic form could be convered into its hydrophilic counterpart.
D000313:Adrenal Medulla / Q000201:enzymology*; D000818:Animals; D000941:Antigens / Q000032:analysis*; D002417:Cattle; D002837:Chromaffin Granules / Q000201:enzymology; D002918:Chymotrypsin; D004299:Dopamine beta-Hydroxylase / Q000276:immunology*; D007123:Immunoelectrophoresis, Two-Dimensional; D007527:Isoenzymes / Q000276:immunology*; D012685:Sepharose / Q000031:analogs & derivatives; D013820:Thermolysin; D014357:Trypsin; D014867:Water
D000941:Antigens; D007527:Isoenzymes; D014867:Water; C020927:phenyl-sepharose; D012685:Sepharose; D004299:Dopamine beta-Hydroxylase; D002918:Chymotrypsin; D014357:Trypsin; D013820:Thermolysin