Surprising insights that aren't so surprising in the modeling of sulfur amino acid metabolism.

The modeling of whole organism sulfur amino acid flux control has been aided in recent years by advancements in proteomics and mass spectroscopy-based metabolite analysis. The convergence of these two fields and their respective techniques, as demonstrated by a new study using yeast by Lafaye et al., has shown that researchers seeking to model whole cell/organism metabolism should give careful consideration to the relationships connecting enzyme concentration, enzyme activity, substrate concentration, and metabolic flux. In this paper, we outline some of the fundamental concepts for modeling sulfur amino acid metabolism and how they relate to our current understanding of mammalian sulfur amino acid metabolism.