Aspartate Aminotransferase Activity Assay Kit

Supplementary info

Activity summary

Aspartate Aminotransferase (AST) also known as aspartate transaminase or aspartate transferase is an enzyme important for amino acid metabolism. Mechanically it catalyzes the reversible transfer of an amino group from aspartate to α-ketoglutarate forming oxaloacetate and glutamate. AST has a molecular mass of approximately 92 kDa and is expressed in various tissues with high levels found in liver heart muscle and kidneys. Its presence in these tissues highlights its importance in cellular metabolic processes.

Biological function summary

AST facilitates the interconversion between aspartate and oxaloacetate playing a role in the amino acid and urea cycles. Though not part of a large complex AST works closely with similar enzymes such as alanine aminotransferase (ALT) to maintain amino acid balance and support energy production. This enzymatic activity is important in nitrogen metabolism and glutamate use which are necessary for synthesizing other essential molecules within the cell.

Pathways

AST participates in the citric acid cycle and malate-aspartate shuttle enabling efficient energy production and NADH transport. The enzyme assists in converting oxaloacetate a pivotal intermediate in the citric acid cycle to keep the cycle active ensuring efficient cellular respiration. Additionally in the malate-aspartate shuttle AST works alongside malate dehydrogenase to facilitate the transfer of reducing equivalents across the mitochondrial membrane which is essential for ATP generation.

Associated diseases and disorders

Elevated AST levels often indicate liver damage such as in hepatitis or cirrhosis reflecting its significant tissue expression. The enzyme is also linked to myocardial infarction as damaged heart muscle releases AST into the bloodstream. In these conditions AST serves as a biomarker for tissue damage often in conjunction with ALT levels allowing clinicians to assess the extent of liver or cardiac injury.