Premium
Dopamine‐β‐Hydroxylase: Structural Comparisons of Membrane‐Bound Versus Soluble Forms from Adrenal Medulla and Pheochromocytoma
Author(s) -
Sokoloff Roger L.,
Frigon Ronald P.,
O'Connor Daniel T.
Publication year - 1985
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1985.tb05431.x
Subject(s) - adrenal medulla , chromatography , chemistry , concanavalin a , trypsin , amino acid , biochemistry , pheochromocytoma , polyacrylamide gel electrophoresis , sepharose , catecholamine , dopamine , enzyme , biology , endocrinology , in vitro
Dopamine‐β‐hydroxylase (DBH) in membrane‐bound (mDBH) and water‐soluble (sDBH) forms was isolated from chromaffin granules of bovine adrenal medullae and a human pheochromocytoma tumor. sDBH was purified by concanavalin A‐agarose column chromatography followed by DEAE‐Sepharose column chromatography. The final bovine preparation had a specific activity of 16.27 IU/mg; the human preparation had a specific activity of 9.16 IU/mg. mDBH was isolated in enzymatically inactive form by preparative polyacrylamide gel electrophoresis. The proteins were subjected to amino acid analysis, as well as digestion with trypsin, followed by separation of the resulting peptides by twodimensional TLC/electrophoresis. No intraspecies differences between sDBH and mDBH were found from comparisons of amino acid composition or peptide maps. Thus the basis of the difference between sDBH and mDBH cannot easily be explained by differences in primary structure, within the resolution of these techniques.