d-Ribulose-1,5-bisphosphate carboxylase-oxygenase: Improved methods for the activation and assay of catalytic activities
✍ Scribed by G.H. Lorimer; M.R. Badger; T.J. Andrews
- Publisher
- Elsevier Science
- Year
- 1977
- Tongue
- English
- Weight
- 580 KB
- Volume
- 78
- Category
- Article
- ISSN
- 0003-2697
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✦ Synopsis
Improved methods for the activation and assay of D-ribulose-1,5-bisphosphate carboxylase and oxygenase are described. The importance of fully activating the enzyme before starting either reaction is emphasized. The enzyme is activated by preincubation with 20 mM M&l, and 10 mM NaHCO,, pH 8.6. To avoid inactivation effects, both assays are limited to a l-or 2-min duration. The initial rate of carboxylation is determined by a modification of the conventional WO, fixation method, while the initial rate of oxygenase activity is measured polarographically.
Both assays are initiated by the addition of the fully activated enzyme to otherwise complete reaction mixtures. The use of a "CO,free" oxygenase reaction mixture is emphasized along with the difficulties arising from the inevitable carryover of CO, into the reaction mixture with the activated enzyme.