transamination
Last reviewed 01/2018
Transamination describes the reactions involved in the passage of amino (-NH2) groups from amino acids to alpha-keto acids. This converts the amino acid into an alpha-keto acid, and vice versa.
There are a number of enzymes - aminotransferases - involved with transamination. Their presence does not necessarily indicate that a particular amino acid is metabolized by this route. Amino acids such as histidine and serine are degraded by alternative routes.
If 2-oxoglutarate acts as the receiving alpha-keto acid, it is converted to glutamate. It may be reconverted back to 2-oxoglutarate by the action of glutamate dehydrogenase with the production of ammonia. This facilitates transamination by providing more substrate. Ammonia can be passed to the urea cycle.