Publications

• Purification and Characterization of Cystine Lyase a from Broccoli Inflorescence.

  Ukai K., Sekiya J.

  One of the three isoforms of an enzyme degrading L-cystine was purified to homogeneity from broccoli (Brassica oleracea var. italica) inflorescences, with use of a sensitive assay based on derivatization of a reaction product with monobromobimane. The reaction product with a thiol group was found ... >> More

  One of the three isoforms of an enzyme degrading L-cystine was purified to homogeneity from broccoli (Brassica oleracea var. italica) inflorescences, with use of a sensitive assay based on derivatization of a reaction product with monobromobimane. The reaction product with a thiol group was found to be thiocysteine from results of liquid chromatography-mass spectrometry and high-resolution mass spectrometry. Pyruvate was also a reaction product, formed in equimolar amounts. The purified enzyme catalyzed β-elimination of L-cystine to yield thiocysteine, pyruvate and possibly ammonia, so it was cystine lyase a. L-Cystine but not D-cystine was a substrate of the enzyme. S-Methyl L-cysteine sulfoxide and S-ethyl L-cysteine sulfoxide were substrates but were less suitable than L-cystine. L- and D-cysteine and also cystathionine were not substrates. The purified enzyme (Mr 186,000) was composed of four identical subunits (Mr 45,000) and was pyridoxal 5'-phosphate-dependent. << Less

  Biosci Biotechnol Biochem 61:1890-1895(1997) [PubMed] [EuropePMC]

  This publication is cited by 1 other entry.

• A new member of plant CS-lyases. A cystine lyase from Arabidopsis thaliana.

  Jones P.R., Manabe T., Awazuhara M., Saito K.

  Cystine lyases catalyze the breakdown of l-cystine to thiocysteine, pyruvate, and ammonia. Until now there are no reports of the identification of a plant cystine lyase at a molecular level, and it is not clear what biological role this class of enzymes have in plants. A cystine lyase was isolated ... >> More

  Cystine lyases catalyze the breakdown of l-cystine to thiocysteine, pyruvate, and ammonia. Until now there are no reports of the identification of a plant cystine lyase at a molecular level, and it is not clear what biological role this class of enzymes have in plants. A cystine lyase was isolated from Brassica oleracea (L.), and partial amino acid sequencing allowed the corresponding full-length cDNA (BOCL3) to be cloned. The deduced amino acid sequence of BOCL3 showed highest homology to the deduced amino acid sequences of several Arabidopsis thaliana genes annotated as tyrosine aminotransferase-like, including a coronatine, jasmonic acid, and salt stress-inducible gene, CORI3 (78.8% identity), and the unidentified rooty/superroot1 gene (44.8% identity). A full-length expressed sequence tag clone of CORI3 was obtained and recombinant CORI3 was synthesized in Escherichia coli. Isolated recombinant CORI3 catalyzed a cystine lyase reaction, but no aminotransferase reactions. The present study identifies, for the first time, a cystine lyase from plants at a molecular level and redefines the functional assignment of the only functionally identified member of a group of A. thaliana genes annotated as tyrosine aminotransferase-like. << Less

  J. Biol. Chem. 278:10291-10296(2003) [PubMed] [EuropePMC]

  This publication is cited by 1 other entry.