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Oxidative inactivation of reduced NADP-generating enzymes in E. coli: iron-dependent inactivation with affinity cleavage of NADP-isocitrate dehydrogenase.
Arch Microbiol. 2006 Nov; 186(5):385-92.AM

Abstract

Treatment of E. coli extract with iron/ascorbate preferentially inactivated NADP-isocitrate dehydrogenase without affecting glucose-6-phosphate dehydrogenase. NADP-Isocitrate dehydrogenase required divalent metals such as Mg(2+), Mn(2+)or Fe(2+) ion. Iron/ascorbate-dependent inactivation of the enzyme was accompanied with the protein fragmentation as judged by SDS-PAGE. Catalase protecting the enzyme from the inactivation suggests that hydroxyl radical is responsible for the inactivation with fragmentation. TOF-MS analysis showed that molecular masses of the enzyme fragments were 36 and 12, and 33 and 14 kDa as minor components. Based on the amino acid sequence analyses of the fragments, cleavage sites of the enzyme were identified as Asp307-Tyr308 and Ala282-Asp283, which are presumed to be the metal-binding sites. Ferrous ion bound to the metal-binding sites of the E. coli NADP-isocitrate dehydrogenase may generate superoxide radical that forms hydrogen peroxide and further hydroxyl radical, causing inactivation with peptide cleavage of the enzyme. Oxidative inactivation of NADP-isocitrate dehydrogenase without affecting glucose 6-phosphate dehydrogenase shows only a little influence on the antioxidant activity supplying NADPH for glutathione regeneration, but may facilitate flux through the glyoxylate bypass as the biosynthetic pathway with the inhibition of the citric acid cycle under aerobic growth conditions of E. coli.

Authors+Show Affiliations

Department of Biochemistry, Aichi Medical University School of Medicine, Nagakute, Aichi 480-1195, Japan.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article

Language

eng

PubMed ID

16897033

Citation

Murakami, Keiko, et al. "Oxidative Inactivation of Reduced NADP-generating Enzymes in E. Coli: Iron-dependent Inactivation With Affinity Cleavage of NADP-isocitrate Dehydrogenase." Archives of Microbiology, vol. 186, no. 5, 2006, pp. 385-92.
Murakami K, Tsubouchi R, Fukayama M, et al. Oxidative inactivation of reduced NADP-generating enzymes in E. coli: iron-dependent inactivation with affinity cleavage of NADP-isocitrate dehydrogenase. Arch Microbiol. 2006;186(5):385-92.
Murakami, K., Tsubouchi, R., Fukayama, M., Ogawa, T., & Yoshino, M. (2006). Oxidative inactivation of reduced NADP-generating enzymes in E. coli: iron-dependent inactivation with affinity cleavage of NADP-isocitrate dehydrogenase. Archives of Microbiology, 186(5), 385-92.
Murakami K, et al. Oxidative Inactivation of Reduced NADP-generating Enzymes in E. Coli: Iron-dependent Inactivation With Affinity Cleavage of NADP-isocitrate Dehydrogenase. Arch Microbiol. 2006;186(5):385-92. PubMed PMID: 16897033.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Oxidative inactivation of reduced NADP-generating enzymes in E. coli: iron-dependent inactivation with affinity cleavage of NADP-isocitrate dehydrogenase. AU - Murakami,Keiko, AU - Tsubouchi,Ryoko, AU - Fukayama,Minoru, AU - Ogawa,Tadashi, AU - Yoshino,Masataka, Y1 - 2006/08/05/ PY - 2006/02/19/received PY - 2006/07/10/accepted PY - 2006/07/03/revised PY - 2006/8/10/pubmed PY - 2007/9/29/medline PY - 2006/8/10/entrez SP - 385 EP - 92 JF - Archives of microbiology JO - Arch Microbiol VL - 186 IS - 5 N2 - Treatment of E. coli extract with iron/ascorbate preferentially inactivated NADP-isocitrate dehydrogenase without affecting glucose-6-phosphate dehydrogenase. NADP-Isocitrate dehydrogenase required divalent metals such as Mg(2+), Mn(2+)or Fe(2+) ion. Iron/ascorbate-dependent inactivation of the enzyme was accompanied with the protein fragmentation as judged by SDS-PAGE. Catalase protecting the enzyme from the inactivation suggests that hydroxyl radical is responsible for the inactivation with fragmentation. TOF-MS analysis showed that molecular masses of the enzyme fragments were 36 and 12, and 33 and 14 kDa as minor components. Based on the amino acid sequence analyses of the fragments, cleavage sites of the enzyme were identified as Asp307-Tyr308 and Ala282-Asp283, which are presumed to be the metal-binding sites. Ferrous ion bound to the metal-binding sites of the E. coli NADP-isocitrate dehydrogenase may generate superoxide radical that forms hydrogen peroxide and further hydroxyl radical, causing inactivation with peptide cleavage of the enzyme. Oxidative inactivation of NADP-isocitrate dehydrogenase without affecting glucose 6-phosphate dehydrogenase shows only a little influence on the antioxidant activity supplying NADPH for glutathione regeneration, but may facilitate flux through the glyoxylate bypass as the biosynthetic pathway with the inhibition of the citric acid cycle under aerobic growth conditions of E. coli. SN - 0302-8933 UR - https://www.unboundmedicine.com/medline/citation/16897033/Oxidative_inactivation_of_reduced_NADP_generating_enzymes_in_E__coli:_iron_dependent_inactivation_with_affinity_cleavage_of_NADP_isocitrate_dehydrogenase_ L2 - https://dx.doi.org/10.1007/s00203-006-0153-1 DB - PRIME DP - Unbound Medicine ER -