title: Endoglycosidase H susceptibility of secreted and intracellular forms of dopamine beta-hydroxylase.
abstract: In an attempt to characterize the differences between various forms of dopamine beta-hydroxylase (DBH) the endoglycosidase H (endo H) susceptibilities of the intracellular and secreted DBH were compared. Both soluble and membrane-bound forms of newly synthesized DBH in PC12 cells were found to be susceptible to endo H. Soluble DBH, apparent Mr of 73K, was converted to 67K Mr and membrane-bound DBH, apparent Mr of 77K and 73K, shifted to 69K and 67K. Upon stimulation with the potent secretagogue, BaCl2, over 65% of intracellular dopamine and norepinephrine were secreted together with the soluble proteins of the secretory granules. DBH, released upon this stimulated secretion, was relatively resistant to endo H compared to the intracellular forms.
authors.affiliation: Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla 10595.
authors.forename: E L
authors.initials: EL
authors.lastname: Sabban
authors.forename: A
authors.initials: A
authors.lastname: McMahon
authors.forename: L J
authors.initials: LJ
authors.lastname: Kuhn
mesh_terms: D000118:Acetylglucosaminidase / Q000494:pharmacology*; D000818:Animals; D002460:Cell Line; D002462:Cell Membrane / Q000201:enzymology; D004298:Dopamine / Q000493:pharmacokinetics; D004299:Dopamine beta-Hydroxylase / Q000378:metabolism*; D006596:Hexosaminidases / Q000494:pharmacology*; D017038:Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase; D009638:Norepinephrine / Q000493:pharmacokinetics; D051381:Rats
chemical_list: D004299:Dopamine beta-Hydroxylase; D006596:Hexosaminidases; D000118:Acetylglucosaminidase; D017038:Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase; D004298:Dopamine; D009638:Norepinephrine