Aspartate Aminotransferase (AST) is an enzyme found in the liver and other tissues. Elevated levels of AST may indicate liver damage or disease.

iollo markers that associate with Aspartate Aminotransferase (AST)


Alanine is a substrate of the AST enzyme, which catalyzes the transfer of an amino group from alanine to α-ketoglutarate, generating pyruvate and glutamate. Elevated AST levels can indicate increased catabolism of alanine and may be a marker of liver damage or disease.

Aspartic Acid

Aspartate is a direct substrate of the AST enzyme. AST catalyzes the transfer of an amino group from aspartate to α-ketoglutarate, generating oxaloacetate and glutamate. Elevated AST can lead to increased aspartate catabolism and reduced aspartate levels.

Glutamic Acid

Glutamate is a product of the AST reaction, which transfers an amino group from aspartate or alanine to α-ketoglutarate. Increased glutamate levels can result from high AST activity and may indicate liver damage or excessive amino acid catabolism.


Phenylalanine is an essential amino acid that can be catabolized to tyrosine by phenylalanine hydroxylase, with tyrosine subsequently being degraded to fumarate and acetoacetate. Elevated AST may indicate increased amino acid catabolism, including the breakdown of phenylalanine and tyrosine to supply the TCA cycle.


Tyrosine is an amino acid that can be degraded to fumarate and acetoacetate, which can feed into the TCA cycle. Increased AST activity may upregulate amino acid catabolism, including tyrosine breakdown, especially if the liver is damaged or energy demands are high.