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

Role of Synaptic Vesicle Proton Gradient and Protein Phosphorylation on ATP-mediated Activation of Membrane-associated Brain Glutamate Decarboxylase

“…8). Recently we have shown that the taurine synthesizing enzyme, cysteine sulfinic acid decarboxylase behaves similarly to MGAD, namely activation by ATP and protein phosphorylation and inhibition by dephosphorylation (37,38). However, there is a major difference between cysteine sulfinic acid decarboxylase and MGAD in that the former is regulated by product inhibition, whereas the latter is not affected by its product, GABA, even at a concentration of 25 mM (Table I).…”

Protein Phosphorylation and Taurine BiosynthesisIn VivoandIn Vitro

“…The reaction mixture was incubated at 37°C for 60 min and then centrif uged for 10 min at 14,000 rpm. The supernatant solution obtained was applied to an anti-C SAD IgG immunoaffinity column and eluted as described (Bao et al, 1994;Tang et al, 1996). For calf intestine phosphatase (CI P) treatment, 200 U CI P was added to the affinity column as described previously (Bao et al, 1994(Bao et al, , 1995.…”

“…3). Furthermore, PKC -mediated activation of C SAD activity was abol- (Tang et al, 1996). The standard molecular weight markers (in kilodaltons) are also indicated.…”

“…Autoradiograph of C SAD in highly purified preparations. Purified C SAD obtained as described (Tang et al, 1996) was phosphorylated using conditions similar to those described (Bao et al, 1994(Bao et al, , 1995, except that exogenous kinase and CI P were included as indicated. Purified CSAD was treated under the following conditions.…”

Creating a New Pathway inCorynebacterium glutamicumfor the Production of Taurine as a Food Additive

“…In this pathway, taurine is synthesized by the l -cysteine sulfinic acid pathway from the l -cysteine substrate. ,,, In the l -cysteine sulfinic acid pathway, l -cysteine is oxidized to l -cysteine sulfinic acid by l -cysteine dioxygenase (CDO) . Subsequently, l -cysteine sulfinic acid is decarboxylated to hypotaurine by l -cysteine sulfinic acid decarboxylase (CSAD), followed by spontaneous oxidation to taurine (Figure A). , In nonmammals, the taurine biosynthetic pathway remains poorly studied . Several taurine biosynthetic pathways have been reported in chick and fish, which convert the 2-aminoacrylate-derived l -cysteine sulfonic acid ( l -cysteic acid) to taurine by CSAD or l -cysteine sulfonic acid decarboxylase (CAD) (Figure B). , The two metabolic pathways of the mammals and some nonmammals were significantly different in the starting metabolites such as l -methionine and l -serine, enzymes involved in taurine biosynthesis, intermediates, cofactors, and so on (Figure A,B).…”