Glutamic-Oxalacetic Transaminase from porcine heart

Research area: Cellsignaling. Glutamic-Oxalacetic Transaminase is found in all tissues and is predominant in the liver and skeletal muscle. It is a prototype of fold-type I pyridoxal 5′-phosphate (PLP)-enzymes. Glutamic-oxalacetic transaminase is a homodimer containing large and small domains in each subunit.

Glutamic-OxalaceticTransaminase from porcine heart is suitable for the preparation ofphenylalanine amino acid. The immobilized form of this enzyme maybe used incomparison studies between soluble and immobilized forms in terms of reactionefficiency and stability.

Glutamic-Oxalacetic Transaminase from porcine heart has been used:

• in an enzyme-coupled assay for evaluating L-asparaginase enzyme activity
• in microtiter plate format enzyme-based assay to estimate malic acid content in berry samples
• as a supplement in homogenization buffers for the isolation of heart mitochondrial membranes in the presence of oxaloacetate (OAA)-depleting system

Glutamic-oxalacetic transaminase or aspartate aminotransferase (AAT) catalyzes the interconversion of L-aspartate and α-ketoglutarate with oxalacetate and L-glutamate. This reversible transaminase reaction is dependent on pyridoxal 5′-phosphate (PLP). Glutamic-oxalacetic transaminase maintains the nitrogen currency for metabolism by generating L-glutamate. Elevated serum levels of glutamic-oxalacetic transaminase are indicated in myocardial infarction, liver diseases, and some renal diseases.

Suspension in 3.0 M (NH₄)₂SO₄ containing 0.05 M maleate and 2.5 mM α-ketoglutarate, pH 6.0

Protein determined by biuret.

One unit will convert 1.0 μmole of α-ketoglutarate to L-glutamate per min at pH 7.5 at 37 °C, in the presence of L-aspartic acid. One unit is equivalent to ~2,000O.D. (Karmen) units at 25 °C.