The Active Center of Aspartate Transaminase

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...

Urinary aspartate transaminase in childhood.

Carbamylation of aspartate transaminase and the pK value of the active site lysyl residue.

Abnormal lysyl residues can be detected in aspartate transaminase by following the rate of reaction of amino groups with KN14CO and the rate of enzymatic inactivation. Peptide isolation subsequent to carbamylation of the apoenzyme produces a peptide which is absent in the carbamylated holoenzyme. The composition of the carbamylated peptide matches that of a tryptic peptide containing the active...

Differential scanning calorimetry of cytoplasmic aspartate transaminase.

Differential scanning calorimetry has been applied to study factors affecting the thermally induced denaturation of cytoplasmic aspartate aminotransferase, a dimeric pyridoxal enzyme. The consequences of binding of coenzyme and substrate derivatives to both the apo and holo forms of the enzyme were investigated and are interpreted in terms of the stabilization of the native form of the enzyme. ...

Evidence of phenylalanine transaminase activity in the isoenzymes of aspartate transaminase.

The transamination by pig mitochondrial and supernatant aspartate transaminase of aromatic amino acids was studied in order to determine if an analogy exists between these enzymes and a previously reported brain phenylalanine transaminase (GEORGE, H., AND GABAY, S. (1968) Biochim. Biophys. Ada, 167, 555). Supernatant and mitochondrial aspartate transaminase from pig heart can utilize aromatic a...