- 作者: Xiao Wen Tang; Che-Chang Hsu; Yong Sun; Elliott Wu; Chao-Yuh Yang; Jang-Yen Wu
- 作者服務機構: a Department of Physiology and Cell Biology, University of Kansas, Lawrence, Kans., and; b Department of Medicine, Baylor College of Medicine, Houston, Tex., USA
- 中文摘要: --
- 英文摘要: 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 Mn2+, 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 comi-grated 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 Mn2+ for its maximum activity. Other divalent cations fail to replace Mn2+ in activation of CSAD activity. However, the precise role of Mn2+ in the action of CSAD remains to be determined.
- 中文關鍵字: --
- 英文關鍵字: Taurine; Cysteine sulfinic acid decarboxylase ; GABA; L-Glutamate decarboxylase ; Mn2+