title: Multiplicity of Brain Cysteine Sulfinic Acid Decarboxylase - Purification, Characterization and Subunit Structure.
abstract: Cysteine sulfinic acid decarboxylase (CSAD), the rate-limiting enzyme in taurine biosynthesis, appears to be present in the brain in multiple isoforms. Two distinct forms of CSAD, referred to as CSAD I and CSAD II, were obtained on Sephadex G-100 column. CSAD I and CSAD II differ in: (1) the elution profile on Sephadex G-100 column; (2) the sensitivity towards Mn(2+), methione, and other sulfur-containing amino acids, and (3) their immunologic properties. CSAD II has been purified to about 2,500-fold by a combination of column chromatographies and polyacrylamide gel electrophoresis (PAGE). The purity of the enzyme preparation was established as judged from the following observations: (1) a single protein band was observed under various electrophoretic conditions, e.g., 5-20% nondenaturing PAGE, 7% nondenaturing PAGE and 10% SDS-PAGE, and (2) in nondenaturing PAGE, the protein band comigrated with CSAD activity. CSAD II has a molecular weight of 90 kDa and is a homodimer consisting of two 43 +/- 2 kDa subunits. CSAD appears to require Mn(2+) for its maximum activity. Other divalent cations fail to replace Mn(2+) in activation of CSAD activity. However, the precise role of Mn(2+) in the action of CSAD remains to be determined. Copyright 1996 S. Karger AG, Basel
authors.affiliation: Department of Physiology and Cell Biology, University of Kansas, Lawrence, Kans., USA.
authors.forename: X.W.
authors.initials: XW
authors.lastname: Tang
authors.forename: C.-C.
authors.initials: CC
authors.lastname: Hsu
authors.forename: Y.
authors.initials: Y
authors.lastname: Sun
authors.forename: E.
authors.initials: E
authors.lastname: Wu
authors.forename: C.-Y.
authors.initials: CY
authors.lastname: Yang
authors.forename: J.-Y.
authors.initials: JY
authors.lastname: Wu