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||"Here [investigators] describe a global view of enzyme parameters
with the aim of highlighting the forces that shape the catalytic
efficiency of enzymes."
||"The median KM is ~100µM (Figure 1C BNID 111413), where ~60% of all KM values are in the range of 10-1000µM. The distribution of KM values implies an empirical constraint for the KM of metabolic enzymes toward their substrates, where the vast majority of enzymes (>99%) do not exhibit KM values below 0.1µM. Such a low KM characterizes, for example, the glycolysis enzymes glyceraldehyde-3-phosphate dehydrogenase and phosphoglycerate kinase utilizing the substrate 1,3-bisphosphoglycerate, the cellular concentration of which is ~0.1µM. [primary source]"