The extensive literature on the occurrence of malic acid in plant tissues was reviewed by Franeen and Keyssner (1) in 1923. Although they found that the conclusive tests of isolation and chemical identification had been applied in relatively few cases, there is no question that this acid is widely distributed in nature and is of great importance in plant metabolism. In those instances in which ...

Extracts of liver and muscle convert citric acid into laevo-rotatory isocitric acid [Martius, 1938]. As the rotation of isocitric acid, like that ofother ac-hydroxy acids, is much increased by (NH4)2MoO4*, the polarimeter can be used to measure low concentrations of isocitric acid in tissue extracts [Martius, 1938; Jacobsohn, 1940]. On applying this method to plant extracts we met with an unexp...

Mutants of Escherichia coli lacking malic dehydrogenase activity (mdh) were incapable of growth on acetate", succinate- or malate/mineral medium. Revertants of mdh strains which had regained the ability to grow on C4-dicarboxylic acids could be divided into two distinct classes. One type of revertant had regained the ability to synthesize functional malic dehydrogenase. The other type of revert...

The formation of diastereomeric cocrystals of malic acid and tartaric acid was investigated by liquid-assisted grinding in the solid state. We demonstrate that racemic malic acid can be converted into two distinct diastereomeric cocrystal phases by grinding with a single enantiomer of tartaric acid.

The optimal ratio of L-malic and L-tartaric acid in relation to other wine components is one of the most important aspects that ultimately determine wine quality during winemaking. Winemakers routinely rely on the judicious use of malolactic fermentation (MLF) after alcoholic fermentation to deacidify and stabilise their wines. However, due to the unreliability of the process and unsuitable sen...

The NAD(+)-dependent malic enzyme (DME) and the NADP(+)-dependent malic enzyme (TME) of Sinorhizobium meliloti are representatives of a distinct class of malic enzymes that contain a 440-amino-acid N-terminal region homologous to other malic enzymes and a 330-amino-acid C-terminal region with similarity to phosphotransacetylase enzymes (PTA). We have shown previously that dme mutants of S. meli...

In chick embryo hepatocytes (CEH), stimulation of malic enzyme transcription by 3,3',5-tri-iodothyronine (T3) is mediated by a liver-specific and T3-inducible DNase I hypersensitive region (-3910 to -3640 bp) in the malic enzyme gene. Previous studies have shown that this region contains a cluster of five T3 response elements (T3REs), referred to as a T3 response unit (T3RU), plus three accesso...

Previous studies in vivo have demonstrated that in neonatal and adult rats hepatic malic enzyme expression is controlled at the pretranslational level by dietary and hormonal factors [ 1, 21. However, in order to demonstrate that particular effectors have a direct effect on gene expression in liver cells, techniques in vitro, such as the use of primary cultures of non-proliferating rat hepatocy...