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Vitamin B 6 enzymes participating in selenium amino acid metabolism
Author(s) -
Soda Kenji,
Oikawa Tadao,
Esaki Nobuyoshi
Publication year - 1999
Publication title -
biofactors
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.204
H-Index - 94
eISSN - 1872-8081
pISSN - 0951-6433
DOI - 10.1002/biof.5520100225
Subject(s) - selenocysteine , cysteine , biochemistry , cystathionine beta synthase , lyase , enzyme , chemistry , methionine , amino acid , selenium , pyridoxal , metabolism , cysteine metabolism , pyridoxal phosphate , cofactor , organic chemistry
Various vitamin B 6 enzymes play important roles in mammalian and microbial metabolism of selenium amino acids. Selenocysteine is synthesized from selenohomocysteine by catalysis of cystathionine β‐synthase and cystathionine γ‐lyase, which both require pyridoxal phosphate. Selenocysteine β‐lyase, a new B 6 ‐enzyme, exclusively catalyzes β‐elimination of selenocysteine, and occurs in mammalian systems and bacteria. Methionine γ‐lyase, cysteine desulfurase, cysteine sulfinate desulfinase, and D‐selenocystine α, β‐lyase, which are B 6 ‐enzymes, act on cysteine, cysteine sulfinate, D‐cystine, and their derivatives, and their selenium counterparts indiscriminately. Their reaction mechanisms are comparatively described.