{"id":2771,"date":"2013-10-22T06:27:29","date_gmt":"2013-10-22T06:27:29","guid":{"rendered":"https:\/\/mycor.iam.inrae.fr\/IAM\/?p=2771"},"modified":"2013-10-23T15:44:02","modified_gmt":"2013-10-23T15:44:02","slug":"articleplant-physiology-and-biochemistry","status":"publish","type":"post","link":"https:\/\/mycor.iam.inrae.fr\/IAM\/?p=2771","title":{"rendered":"Article: Plant Physiology and Biochemistry"},"content":{"rendered":"

Overexpression, purification and enzymatic characterization of a recombinant plastidial glucose-6-phosphate dehydrogenase from barley (< i> Hordeum vulgare<\/i> cv. Nure) roots<\/a>
\nM Cardi, K Chibani, D Castiglia, D Cafasso, E Pizzo, N Rouhier, JP Jacquot …
\nPlant Physiology and Biochemistry<\/p>\n

Abstract<\/h2>\n

In plant cells, the plastidial glucose 6-phosphate dehydrogenase (P2-G6PDH, EC 1.1.1.49) represents one of the most important sources of NADPH. However, previous studies revealed that both native and recombinant purified P2-G6PDHs show a great instability and a rapid loss of catalytic activity. Therefore it has been difficult to describe accurately the catalytic and physico-chemical properties of these isoforms.<\/p>\n

The plastidial G6PDH encoding sequence from barley roots (Hordeum vulgare<\/em>\u00a0cv. Nure), devoid of a long plastidial transit peptide, was expressed as recombinant protein in\u00a0Escherichia coli<\/em>, either untagged or with an N-terminal his-tag. After purification from both the soluble fraction and inclusion bodies, we have explored its kinetic parameters, as well as its sensitivity to reduction.<\/p>\n

The obtained results are consistent with values determined for other P2-G6PDHs previously purified from barley roots and from other land plants. Overall, these data shed light on the catalytic mechanism of plant P2-G6PDH, summarized in a proposed model in which the sequential mechanism is very similar to the mammalian cytosolic G6PDH.<\/p>\n

This study provides a rational basis to consider the recombinant barley root P2-G6PDH as a good model for further kinetic and structural studies.<\/p>\n

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Keywords<\/h2>\n