The cDNA encoding the 65-kDa subunit of malic enzyme from Ascaris suum was cloned into the bacterial expression vector pKK223-3 and overproduced in Escherichia coli. A protein with a subunit molecular mass of 65,000 was expressed at a level of up to 3% of the total soluble protein in JM109, as judged by SDS-PAGE. The enzyme was purified using column chromatography on phenyl-Sepharose followed by orange-A agarose. The purification procedure resulted in a 32-fold purification with an overall yield of 51%. The bacterially expressed enzyme exhibits kinetic constants identical to those measured for native A. suum NAD-malic enzyme.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1006/prep.1996.0705 | DOI Listing |
Plant Cell Environ
September 2024
Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada.
C NAD-malic enzyme (NAD-ME) species occurs in drier regions and exhibit different drought responses compared to C NADP-malic enzyme (NADP-ME) species. However, a physiological mechanism explaining the geographical discrepancies remains uncertain. This study examined gas exchange patterns that might explain different distributions observed between two subtypes of C photosynthesis.
View Article and Find Full Text PDFPlant Cell Environ
June 2024
Lancaster Environment Centre, Lancaster University, Lancaster, UK.
The repeated emergence of NADP-malic enzyme (ME), NAD-ME and phosphoenolpyruvate carboxykinase (PEPCK) subtypes of C photosynthesis are iconic examples of convergent evolution, which suggests that these biochemistries do not randomly assemble, but are instead specific adaptations resulting from unknown evolutionary drivers. Theoretical studies that are based on the classic biochemical understanding have repeatedly proposed light-use efficiency as a possible benefit of the PEPCK subtype. However, quantum yield measurements do not support this idea.
View Article and Find Full Text PDFPlant Physiol
November 2023
Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
Common purslane (Portulaca oleracea) integrates both C4 and crassulacean acid metabolism (CAM) photosynthesis pathways and is a promising model plant to explore C4-CAM plasticity. Here, we report a high-quality chromosome-level genome of nicotinamide adenine dinucleotide (NAD)-malic enzyme (ME) subtype common purslane that provides evidence for 2 rounds of whole-genome duplication (WGD) with an ancient WGD (P-β) in the common ancestor to Portulacaceae and Cactaceae around 66.30 million years ago (Mya) and another (Po-α) specific to common purslane lineage around 7.
View Article and Find Full Text PDFFront Plant Sci
April 2023
Department of Biology, Faculty of Science, Ege University, Bornova, Izmir, Türkiye.
Single cell C (SCC) plants, discovered around two decades ago, are promising materials for efforts for genetic engineering of C photosynthesis into C crops. Unlike C plants with Kranz anatomy, they exhibit a fully functional C photosynthesis in just a single cell and do not require mesophyll and bundle sheath cell spatial separation. is one such SCC plant, with NAD-malic enzyme (NAD-ME) subtype C photosynthesis.
View Article and Find Full Text PDFPlant Biol (Stuttg)
June 2023
Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan.
C plants supply concentrated CO to bundle sheath (BS) cells, improving photosynthetic efficiency by suppressing photorespiration. Mesophyll chloroplasts in C plants are redistributed toward the sides of the BS cells (aggregative movement) in response to environmental stresses under light. Although this chloroplast movement is common in C plants, the significance and mechanisms underlying the aggregative movement remain unknown.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!