Research output: Contribution to Journal/Magazine › Journal article › peer-review
<mark>Journal publication date</mark> | 1/01/1992 |
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<mark>Journal</mark> | Biochemical Journal |
Issue number | 3 |
Volume | 287 |
Number of pages | 5 |
Pages (from-to) | 821-825 |
Publication Status | Published |
<mark>Original language</mark> | English |
An enzyme that releases P. from 2-carboxy-D-arabinitol l-phosphate, a naturally occurring tightly binding inhibitor of ribulose 1,5-bisphosphate carboxylase/oxygenase (EC 4. 1.1. 39), was purified from leaves of French bean seedlings. It was a monomeric protein of M(r) about 56000. Catalytic activity was stimulated by increased concentrations of inorganic salts to a maximum at an ionic strength above 0.2. NADPH and D-fructose 1,6-bisphosphate increased the activity of the enzyme in both the presence and absence of 0.2 M-KCl. The pure enzyme did not require dithiothreitol for activity. The pH optimum was 7, the K(m) for 2-carboxy-D-arabinitol l-phosphate was 0.43 mM and the specific activity 6.8 μmol/min per mg of protein. The enzyme had little or no activity against phosphate ester intermediates of photosynthetic metabolism and glycolysis but hydrolysed the 1,5-bisphosphates of 2'-carboxy-D-ribitol and 2'-carboxy-D-arabinitol more rapidly than 2'-carboxy-D-arabinitol 1-phosphate.