NADP-dependent malate enzyme

NADP-dependent malate enzyme
	Split surface / band model of the dimer of ME1 (human) according to PDB 2AW5
	Existing structural data : 2AW5
Mass / length primary structure	572 amino acids
Cofactor	Me 2+ (Mn 2+ , Mg 2+ )
Identifier
Gene name (s)	ME1 , ME3
External IDs	OMIM : 154250 ; UniProt : P48163 ;
Enzyme classification
EC, category	1.1.1.40 , oxidoreductase
Response type	dehydrogenative decarboxylation
Substrate	Malate + NADP +
Products	Pyruvate + CO 2 + NADPH
Occurrence
Parent taxon	Animals, plants, fungi, some bacteria

The NADP ⁺ -dependent malate enzyme is an enzyme found in animals, fungi and plants that catalyzes an important reaction to provide NADPH in the citrate shuttle . Here, malate to pyruvate implemented. This enzyme, which is present with one isoform in both mitochondria ( ME3 ) and in the cytosol ( ME1 ), can be found in all tissue types in humans. Plants also have two isoforms.

In addition to the NADP ⁺ -dependent malate enzyme, there are malate enzymes that function with NAD: on the one hand, the NAD-dependent malate enzyme (oxaloacetate decarboxylates) , in which NAD ^{+ is} reduced ( EC 1.1.1.38 ). Here, too, oxaloacetate can serve as a substrate. On the other hand, there is also an NAD-dependent malate enzyme in which NAD ^{+ is also} reduced ( EC 1.1.1.39 ), but oxaloacetate cannot be converted. Malate enzymes are not identical to malate dehydrogenase !

Catalyzed reaction

+ NADP ⁺ + NADP H + CO ₂ ${\ displaystyle \ rightleftharpoons}$

L -Malat is decarboxylated to pyruvate , generating an NADPH from an NADP ⁺ . Oxaloacetate is also accepted as a substrate.

Generation of NADPH

In addition to the pentose phosphate pathway occurring enzymes glucose-6-phosphate dehydrogenase , 6-phosphogluconate dehydrogenase and a shape of isocitrate dehydrogenase , as well as glutamate dehydrogenase is the NADP ⁺ -dependent malic enzyme for animals, the only way to generate NADPH.

literature

J. Rassow, Biochemistry, 2nd edition, Thieme 2008
Pongratz RL, Kibbey RG, Shulman GI, Cline GW: Cytosolic and mitochondrial malic enzyme isoforms differentially control insulin secretion . In: J. Biol. Chem. . 282, No. 1, January 2007, pp. 200-7. doi : 10.1074 / jbc.M602954200 . PMID 17102138 .
Vidal O, Varona L, Oliver MA, Noguera JL, Sànchez A, Amills M: Malic enzyme 1 genotype is associated with backfat thickness and meat quality traits in pigs . In: Anim. Genet. . 37, No. 1, February 2006, pp. 28-32. doi : 10.1111 / j.1365-2052.2005.01366.x . PMID 16441292 .
Satterlee J, Hsu RY: Duck liver malic enzyme: sequence of a tryptic peptide containing the cysteine residue labeled by the substrate analogous bromopyruvate . In: Biochim. Biophys. Acta . 1079, No. 3, September 1991, pp. 247-52. PMID 1911848 .

Individual evidence

↑ ^a ^b Swiss Institute of Bioinformatics (SIB): PROSITE documentation PDOC00294. Malic enzymes. Retrieved August 14, 2011 .
↑ UniProt P48163 , UniProt Q16798
^ David Nelson, Michael Cox: Lehninger Biochemie . Springer, Berlin; 4th, completely revised u. exp. Edition 2009; ISBN 978-3-540-68637-8 , p. 1076.

Web links

Wikibooks: Biochemistry and Pathobiochemistry: Biosynthesis of Saturated Fatty Acids - Learning and Teaching Materials

May / reactome: Upregulation of Target Genes by Activated PPARA

[p-1] Swiss Institute of Bioinformatics (SIB): PROSITE documentation PDOC00294. Malic enzymes. Retrieved August 14, 2011 .

[2] UniProt P48163 , UniProt Q16798

[3] David Nelson, Michael Cox: Lehninger Biochemie . Springer, Berlin; 4th, completely revised u. exp. Edition 2009; ISBN 978-3-540-68637-8 , p. 1076.