Catalyzes the oxidative decarboxylation of (S)-malate to pyruvate using NADP(+) as a cofactor (PubMed:7818469). Can also reverse the decarboxylation reaction, but only with significantly lower efficiency (PubMed:7818469). (S)-malate + NADP(+) = CO2 + NADPH + pyruvate H(+) + oxaloacetate = CO2 + pyruvate Divalent metal cations. Prefers magnesium or manganese. Expressed predominantly in organs with a low-division rate. Belongs to the malic enzymes family.