Skip to main content
padlock icon - secure page this page is secure

Free Content Folate salvage in plants: pterin aldehyde reduction is mediated by multiple non-specific aldehyde reductases

Download Article:

You have access to the full text article on a website external to Ingenta Connect.

Please click here to view this article on Wiley Online Library.

You may be required to register and activate access on Wiley Online Library before you can obtain the full text. If you have any queries please visit Wiley Online Library

Summary

Folates undergo oxidative cleavage in vivo, releasing a pterin aldehyde fragment that can be re-used in folate synthesis if the aldehyde group is reduced. High levels of NADPH-dependent reductase activity against pterin-6-aldehyde and its dihydro form were detected in Arabidopsis, pea and other plants; modeling predicted that the activity would maintain in vivo pterin aldehyde pools at extremely low levels (<0.2 pmol g−1 FW). Subcellular fractionation showed that the pea leaf activity is mainly cytosolic, and anion exchange chromatography revealed multiple isoforms, all of which catalyzed reduction of other aldehydes. Arabidopsis seed activity likewise comprised various isoforms. An Arabidopsis gene (At1g10310) encoding a pterin aldehyde reductase was identified by searching the short-chain dehydrogenase/reductase family for proteins predicted to be NADPH-linked, and sharing conserved residues with reductases that mediate analogous reactions. The recombinant protein behaved as a dimer in size exclusion chromatography. In addition to pterin aldehydes, it catalyzed the reduction of diverse aromatic and aliphatic aldehydes: Vmax values varied <5-fold, but Km values ranged from 3.6 μmto 1.7 mm, those for pterin-6-aldehyde and dihydropterin-6-aldehyde being 36 and 56 m, respectively. Activity with dihydropterin-6-aldehyde was unusually high at 0°C. The At1g10310 transcript was most abundant in seeds, but, as expected for multiple isoforms, inactivating the At1g10310 gene caused only a minor change in seed pterin aldehyde reductase activity. We conclude that pterin aldehyde salvage in plants involves multiple, generalist NADPH-linked reductases, and that the At1g10310 enzyme is typical of these and hence suitable for use in engineering studies of folate turnover.
No References
No Citations
No Supplementary Data
No Article Media
No Metrics

Keywords: Arabidopsis; aldehyde reductase; folate salvage; pea; pterin aldehydes

Document Type: Research Article

Affiliations: 1: Horticultural Sciences Department, University of Florida, Gainesville, FL 32611, USA 2: Food Science and Human Nutrition Department, University of Florida, Gainesville, FL 32611, USA

Publication date: August 1, 2007

  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
X
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more