Malate dehydrogenase (decarboxylating)

Malate dehydrogenase (decarboxylating) (EC 1.1.1.39) or NAD-malic enzyme (NAD-ME) is an enzyme that catalyzes the chemical reaction

(S)-malate + NAD⁺ ${\displaystyle \rightleftharpoons }$ pyruvate + CO₂ + NADH

NAD-malic enzyme
malic enzyme tetramer, Human
Identifiers
EC no.	1.1.1.39
CAS no.	9028-46-0
Databases
IntEnz	IntEnz view
BRENDA	BRENDA entry
ExPASy	NiceZyme view
KEGG	KEGG entry
MetaCyc	metabolic pathway
PRIAM	profile
PDB structures	RCSB PDB PDBe PDBsum
Gene Ontology	AmiGO / QuickGO
Search PMC articles PubMed articles NCBI proteins

Thus, the two substrates of this enzyme are (S)-malate and NAD⁺, whereas its three products are pyruvate, CO₂, and NADH. Malate is oxidized to pyruvate and CO₂, and NAD⁺ is reduced to NADH.

This enzyme belongs to the family of oxidoreductases, to be specific, those acting on the CH-OH group of donor with NAD⁺ or NADP⁺ as acceptor. The systematic name of this enzyme class is (S)-malate:NAD⁺ oxidoreductase (decarboxylating). This enzyme participates in pyruvate metabolism and carbon fixation. NAD-malic enzyme is one of three decarboxylation enzymes used in the inorganic carbon concentrating mechanisms of C₄ and CAM plants. The others are NADP-malic enzyme and PEP carboxykinase.^[1][2]