Organelle-specific Isozymes of Aspartate-α-Ketoglutarate Transaminase in Spinach Leaves

Organelle-specific Isozymes of Aspartate-alpha-Ketoglutarate Transaminase in Spinach Leaves.

Four distinct isozymes of aspartate-alpha-ketoglutarate transaminase in a spinach (Spinacia oleracea L.) leaf extract were separated by starch gel electrophoresis. Of the total aspartate-alpha-ketoglutarate transaminase activity, approximately 45% was represented by the chloroplast isozyme, 26% by the cytosol isozyme, 19% by the mitochondrial isozyme, and 3 to 10% by the peroxisomal isozyme. Th...

Subunit structure of lysine sensitive aspartate kinase from spinach leaves.

The lysine-sensitive isoenzyme of aspartate kinase was purified to homogeneity from spinach leaves and its subunit composition was studied. The purified preparation had an apparent molecular mass of 280,000 and separated into two subunits- a large subunit with molecular mass of 53,000 and smaller subunit with molecular mass of 17,000 by urea treatment and SDS PAGE. The enzyme molecule has subun...

Urinary aspartate transaminase in childhood.

Complexes of serine acetyltransferase and isozymes of cysteine synthase in spinach leaves.

Polyclonal antibodies against cysteine synthase (CSase; EC 4.2.99.8) isozymes 1, 2, and 3 were used for the detection of complexes of these isozymes with serine acetyltransferase (SATase; EC 2.3.1.30). SATase was partially purified and found to complex with these isozymes by western blotting and immunotitration. When the complexes were treated with a high concentration of O-acetyl-L-serine, the...

Dffluoro-oxaloacetate with Aspartate Transaminase

Difluoro-oxaloacetate interacts with the aldimine form of aspartate transaminase to give a complex, the dissociation constant ofwhich has been determined spectrophotometrically and by 19F n.m.r. (nuclear magnetic resonance). The 19F n.m.r. line-width-pH and chemical-shift-pH profiles of difluoro-oxaloacetate in the presence of the aldimine form of the enzyme both show inflexion points in the pH...