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The reversible association of quinate:NAD + oxidoreductase from carrot cells with a putative regulatory subunit depends on light conditions
Author(s) -
Graziana Annick,
Ranjeva Raoul,
Salimath Bharathi P.,
Boudet Alain M.
Publication year - 1983
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(83)80841-2
Subject(s) - nad+ kinase , protein subunit , oxidoreductase , enzyme , biochemistry , chaotropic agent , trypsin , chemistry , biology , microbiology and biotechnology , gene
The transfer of carrot cell‐suspension cultures from light to dark conditions provoked considerable and reversible changes in the regulatory and structural properties of quinate:NAD + oxidoreductase. Thus, the enzyme became directly activatable by Ca 2+ and its M r shifted from 42 kDa to 110 kDa. The analysis of the dark enzyme, purified to homogeneity, showed that an additional subunit of 60–63 kDa was associated to QORase. The homogeneous native enzyme retained the sensitivity to calcium. Preincubation with trypsin had no effect on sensitivity to Ca 2+ while a chaotropic agent mimicked the action of Ca 2+ . It is concluded that light—dark transitions provoke the association of QORase with a putative regulatory subunit which may be a calciprotein.