Glutamic-Oxalacetic Transaminase from porcine heart (C15-1289-786)

General description

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.

Application

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

Biochem/physiol Actions

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.

Unit Definition

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.

Physical form

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

Analysis Note

Protein determined by biuret.