# Median kcat/KM number for the entire data set of enzymes and natural substrates

Range | ~10^5 M^-1×sec^-1 |
---|---|

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 3rd 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 turnover number for the entire data set of enzymes and natural substrates is ~10 s^-1 (Figure 1A BNID 111411), where most kcat values (~60%) are in the range of 1-100 s^-1. These rates are orders of magnitude slower than the textbook examples of fast enzymes [e.g., carbonic anhydrase (Figure 1A)], let alone compared to the theoretical limit of 10^6-10^7S^-1. [refs 6,1] The median kcat/KM is ~10^5 M^-1×S^-1 (Figure 1B), where most kcat/KM values (~60%) lie in the range of 10^3-10^6M^-1×S^-1, orders of magnitude below the diffusion limit." |

Entered by | Uri M |

ID | 111412 |