Characterization of NAD-dependent malate dehydrogenases from spinach leaves
Abstract
Spinach leaves were used to extract isoforms of NAD-dependent malate dehydrogenase (NAD-MDH) (EC 1.1.1.37), either soluble or bound to microsomal, plasma, or chloroplast envelope membranes. All fractions were subjected to isoelectric focusing analysis, which showed that purified chloroplast envelopes contain an NAD-MDH isoform tightly bound to the membranes, since treatment with 0.5 or 1% Triton X-100 was not able to release the enzyme from the envelopes. In contrast, plasma membranes released an isoform with a pI of 3.5 following treatment with 0.5% Triton X-100. The most abundant soluble leaf isoform had a pI of 9, while the chloroplast stroma contained an isoform with a pI of 5.3. Kinetic analysis of oxaloacetate (OAA)-dependent NADH oxidation in different fractions gave different K-m values for both substrates, the envelope- and plasma membrane-bound NAD-MDH exhibiting the highest affinities for OAA. Leaf plasma membrane-bound MDH exhibited a high capacity for both reaction directi...ons (malate oxidation and OAA reduction), while the two chloroplast isoforms (stromal and envelope-bound) preferentially reduced OAA. Our results indicate that the chloroplast envelope contains a specifically attached NAD-MDH isoform that could provide direct coupling between chloroplast and cytosol adenylate pools.
Keywords:
Spinacia oleracea / plasma membrane / NAD-dependent malate dehydrogenase / chloroplast envelope membraneSource:
Protoplasma, 2008, 232, 3-4, 247-253Publisher:
- Springer Wien, Wien
DOI: 10.1007/s00709-007-0282-7
ISSN: 0033-183X
PubMed: 18239847
WoS: 000256803900013
Scopus: 2-s2.0-43149091453
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Institution/Community
Institut za multidisciplinarna istraživanjaTY - JOUR AU - Cvetic, T. AU - Veljović-Jovanović, Sonja AU - Vučinić, Željko PY - 2008 UR - http://rimsi.imsi.bg.ac.rs/handle/123456789/243 AB - Spinach leaves were used to extract isoforms of NAD-dependent malate dehydrogenase (NAD-MDH) (EC 1.1.1.37), either soluble or bound to microsomal, plasma, or chloroplast envelope membranes. All fractions were subjected to isoelectric focusing analysis, which showed that purified chloroplast envelopes contain an NAD-MDH isoform tightly bound to the membranes, since treatment with 0.5 or 1% Triton X-100 was not able to release the enzyme from the envelopes. In contrast, plasma membranes released an isoform with a pI of 3.5 following treatment with 0.5% Triton X-100. The most abundant soluble leaf isoform had a pI of 9, while the chloroplast stroma contained an isoform with a pI of 5.3. Kinetic analysis of oxaloacetate (OAA)-dependent NADH oxidation in different fractions gave different K-m values for both substrates, the envelope- and plasma membrane-bound NAD-MDH exhibiting the highest affinities for OAA. Leaf plasma membrane-bound MDH exhibited a high capacity for both reaction directions (malate oxidation and OAA reduction), while the two chloroplast isoforms (stromal and envelope-bound) preferentially reduced OAA. Our results indicate that the chloroplast envelope contains a specifically attached NAD-MDH isoform that could provide direct coupling between chloroplast and cytosol adenylate pools. PB - Springer Wien, Wien T2 - Protoplasma T1 - Characterization of NAD-dependent malate dehydrogenases from spinach leaves EP - 253 IS - 3-4 SP - 247 VL - 232 DO - 10.1007/s00709-007-0282-7 ER -
@article{ author = "Cvetic, T. and Veljović-Jovanović, Sonja and Vučinić, Željko", year = "2008", abstract = "Spinach leaves were used to extract isoforms of NAD-dependent malate dehydrogenase (NAD-MDH) (EC 1.1.1.37), either soluble or bound to microsomal, plasma, or chloroplast envelope membranes. All fractions were subjected to isoelectric focusing analysis, which showed that purified chloroplast envelopes contain an NAD-MDH isoform tightly bound to the membranes, since treatment with 0.5 or 1% Triton X-100 was not able to release the enzyme from the envelopes. In contrast, plasma membranes released an isoform with a pI of 3.5 following treatment with 0.5% Triton X-100. The most abundant soluble leaf isoform had a pI of 9, while the chloroplast stroma contained an isoform with a pI of 5.3. Kinetic analysis of oxaloacetate (OAA)-dependent NADH oxidation in different fractions gave different K-m values for both substrates, the envelope- and plasma membrane-bound NAD-MDH exhibiting the highest affinities for OAA. Leaf plasma membrane-bound MDH exhibited a high capacity for both reaction directions (malate oxidation and OAA reduction), while the two chloroplast isoforms (stromal and envelope-bound) preferentially reduced OAA. Our results indicate that the chloroplast envelope contains a specifically attached NAD-MDH isoform that could provide direct coupling between chloroplast and cytosol adenylate pools.", publisher = "Springer Wien, Wien", journal = "Protoplasma", title = "Characterization of NAD-dependent malate dehydrogenases from spinach leaves", pages = "253-247", number = "3-4", volume = "232", doi = "10.1007/s00709-007-0282-7" }
Cvetic, T., Veljović-Jovanović, S.,& Vučinić, Ž.. (2008). Characterization of NAD-dependent malate dehydrogenases from spinach leaves. in Protoplasma Springer Wien, Wien., 232(3-4), 247-253. https://doi.org/10.1007/s00709-007-0282-7
Cvetic T, Veljović-Jovanović S, Vučinić Ž. Characterization of NAD-dependent malate dehydrogenases from spinach leaves. in Protoplasma. 2008;232(3-4):247-253. doi:10.1007/s00709-007-0282-7 .
Cvetic, T., Veljović-Jovanović, Sonja, Vučinić, Željko, "Characterization of NAD-dependent malate dehydrogenases from spinach leaves" in Protoplasma, 232, no. 3-4 (2008):247-253, https://doi.org/10.1007/s00709-007-0282-7 . .