Spectrophotometric assays were used to determine the activity of glucose 6-phosphate dehydrogenase (G6PDH) , isocitrate dehydrogenase (ICDH) , malate dehydrogenase (MDH) , and malic enzyme
In this case, the lack of malic enzyme
increases malate accumulation and diminishes the formation of pyruvate and of ethanol, which is highly toxic to plants.
Ten enzyme systems in starch gel were analyzed: Aspartate amino Transferase (AAT), Alcohol Dehydrogenase (ADH), Glucose-3-phosphate dehydrogenase (G3PD), Glucose-6-phosphate dehydrogenase (G6PD), Glucose phosphate Isomerase (GPI), Isocitrate Dehydrogenase (IDH), Lactate dehydrogenase (LDH), Malate dehydrogenase (MDH) Malic Enzyme
(ME), Phosphoglucomutase (PGM), and Esterase (EST) in the polyacrylamide gel.
One approach is to transform the key genes for C4 photosynthesis enzymes, such as PEP carboxylase (PEPC) (Hudspeth et al., 1992; Ku et al., 1999; Endo et al., 2008), NADP malic enzyme
(NADP-ME) (Takeuchi et al., 2000; Tsuchida et al., 2001) and pyruvate orthophosphate dikinase (Fukayama et al., 2001; Wang et al., 2012) into C3 plants.
Saccharomyces cerevisiae-derived peptides reduce the activity of enzymes critical to the manufacture of fat from excess energy in foods, particularly glucose-6-phosphate dehydrogenase (G6PD) and malic enzyme
Acetyl-CoA can be used as the carbon source for fatty acid synthesis and oxaloacetate can be converted by malic enzyme
1 to pyruvate that then reenters mitochondria.
In addition HF feeding depressed FAS and malic enzyme
This MDH then undergoes oxidative decarboxylation to form pyruvate and C[O.sub.2], while generating NADPH from [NADP.sup.+] in a reaction catalyzed by malic enzyme
. Reuptake of pyruvate by mitochondria occurs, whereby pyruvate combines with CO2 to regenerate oxaloacetate in a reaction catalyzed by the enzyme pyruvate carboxylase.
Abbreviations PUFAs: Polyunsaturated fatty acids SCO: Single cell oil GLA: [gamma]-linolenic acid AA: Arachidonic acid NADPH: Nicotinamide adenine dinucleotide phosphate AMP: Adenosine monophosphate Acetyl Co-A: Acetyl co-enzyme A ME: Malic enzyme
FAS: Fatty acid synthase ACL: ATP citrate-lyase NAD: ICDH: Nicotinamide adenine dinucleotide: isocitrate dehydrogenase N: Nitrogen C: Carbon X: Biomass (g/L) L: Lipid.
It has been demonstrated that the cytosolic NAD (P)- dependent dehydrogenases6 and NADP malic enzyme
are inhibited by MTX, indicating that the drug could decrease the availability of NADPH in cells by inhibiting pentose cycle enzymes.7 Due to the interference with the pentose phosphate shunt, MTX may also depress nucleic acid metabolism.