Aspartate Aminotransferase (AST)
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
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.
References
References
Satomi Minato-Inokawa, Ayaka Tsuboi-Kaji, Mari Honda, Mika Takeuchi, Kaori Kitaoka, Miki Kurata. Associations of alanine aminotransferase/aspartate aminotransferase with insulin resistance and β-cell function in women. Nutrients (2023). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10185667/
Daisuke Maeda, Naohiro Kagiyama, Koji Jujo, et al.. Aspartate aminotransferase to alanine aminotransferase ratio is associated with frailty and mortality in older patients with heart failure. Scientific Reports (2021). https://www.nature.com/articles/s41598-021-91368-z
Xin Liu, Xia Zha, Chen Ding, et al.. Association between aspartate aminotransferase to alanine aminotransferase ratio and new-onset non-alcoholic fatty liver disease in nonobese Chinese individuals: a population-based longitudinal study. Medicine (Baltimore) (2020). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7690093/
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.
References
References
Xiaoqing Wang, He Li, Lin Ji, Jing Cang, Hang Zhao. Association between aspartate aminotransferase to alanine aminotransferase ratio and the risk of diabetes in Chinese prediabetic population: A retrospective cohort study. NCBI (2023). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9846751/
J. Zhou, M. Zhang, Y. Liu, et al.. GWAS of serum ALT and AST reveals an association of SLC30A10 with liver enzyme levels and risk of extrahepatic bile duct cancer. Nature Communications (2021). https://www.nature.com/articles/s41467-021-24563-1
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.
References
References
ScienceDirect Topics. Aspartate aminotransferase - an overview. ScienceDirect Topics (nan). https://www.sciencedirect.com/topics/neuroscience/aspartate-aminotransferase
ScienceDirect Topics. Aspartate Transaminase - an overview. ScienceDirect Topics (nan). https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/aspartate-transaminase
Llufriu S, Hernández M, Tintoré M, Montalban X. Alanine and aspartate aminotransferase and glutamine metabolism in multiple sclerosis. PLOS ONE (2012). https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0044107
Ellory JC, Fearon KC, Hamprecht B, et al.. Role of aminotransferases in glutamate metabolism of human erythrocytes. Journal of Inherited Metabolic Disease (2011). https://link.springer.com/article/10.1007/s10858-011-9481-9
Phenylalanine
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.
References
References
Kettunen, J., et al.. Liver enzymes, metabolomics and genome-wide association studies. PLoS One (2014). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4299326/
Hu, X., et al.. Molecular analysis of the role of two aromatic aminotransferases and a broad-specificity aspartate aminotransferase in the degradation of phenylalanine. Journal of Biological Chemistry (2009). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2685563/
Zhang, Y., et al.. Ursodeoxycholic acid improves liver function via phenylalanine/tyrosine pathway and microbiome remodelling in patients with liver dysfunction. Scientific Reports (2018). https://www.nature.com/articles/s41598-017-14974-w
Tyrosine
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.
References
References
M. J. Keating, A. J. Renaville, S. C. Reid, M. M. Hultquist, J. D. Raber, J. R. Choi, J. A. Gerlt. Molecular function prediction for a family exhibiting evolutionary tendencies toward substrate specificity swapping: Recurrence of tyrosine aminotransferase activity in the Iα subfamily. Journal of Biological Chemistry (2013). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3823064/
A. M. Miners, M. A. Köttgen, J. A. Satterfield, J. R. Sedor. Liver enzymes, metabolomics and genome-wide association studies. Current Opinion in Genetics & Development (2014). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4299326/