This view shows enzymes only for those organisms listed below, in the list of taxa known to possess the pathway. If an enzyme name is shown in bold, there is experimental evidence for this enzymatic activity.
|Superclasses:||Degradation/Utilization/Assimilation → Amino Acids Degradation → Proteinogenic Amino Acids Degradation → L-asparagine Degradation|
Expected Taxonomic Range: Embryophyta
Asparagine is the first amino acid discovered in plants, where it is the major nitrogen transport and storage compound. In plants, asparagine is metabolized in two routes, via asparaginase (L-asparagine degradation I) or via asparagine aminotransferase (this pathway). Studies in pea suggested that the predominant route differs in different tissues. The asparaginase pathway predominates in seeds, whereas the aminotransferase pathway predominates in leaves [Ireland81].
In the asparagine aminotransferase pathway, the product 2-oxosuccinamate could either be reduced to 2-hydroxysuccinamate or deaminated to oxaloacetate. 2-oxosuccinamate deaminase activity was co-detected with asparagine aminotransferase in soybean leaves [Streeter77]. Whereas, feeding experiment using pea leaves showed a high amount of 2- hydroxysuccinamate formed from asparagines [Lloyd78]. It is not clear which path is more relevant and the consequent reactions that further metabolize 2-hydroxysuccinamate [Ireland83].
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