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Median KM for the entire data set of enzymes and natural substrates

Range	~100 µM
Organism	Generic
Reference	Bar-Even A. et al., The moderately efficient enzyme: evolutionary and physicochemical trends shaping enzyme parameters. Biochemistry. 2011 May 31 50(21):4402-10. doi: 10.1021/bi2002289. p.4403 right column bottom paragraphPubMed ID21506553
Method	"Here [investigators] describe a global view of enzyme parameters with the aim of highlighting the forces that shape the catalytic efficiency of enzymes."
Comments	"The median KM is ~100µM (Figure 1C), 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. [ref 16]"
Entered by	Uri M
ID	111413