Chapter 6 The basis of enzymatic adaptation

摘要: Summary We have discussed six different types of mechanisms that are used to adapt enzyme function allow metabolism respond changing physiological demands or environmental stresses. Although the present discussion has been largely limited enzymes glycolysis, principles equally applicable virtually all aspects metabolic function. In particular, control via reversible protein phosphorylation is proving be widespread for coordination diverse cellular and proteins ( Boyer Krebs, 1987 ). For example, now well known extend membrane ion-channel proteins, regulating both their incorporation into membranes activity once inserted Reuter, Such coordinated over a wide variety processes critical rate depression. Hibernating mammals, retain potential difference as body temperature falls ambient; same species in summer-adapted state, however, just susceptible destructive effects hypothermia on ion regulation humans. The lessons learned from comparative biochemistry many. combinations controls can applied adaptation nearly limitless found overcome almost any constraint meet demand. Increasingly, we applying information gained studies nowhere this more true development organ preservation technology. Both depression freeze tolerance animals directly transplant technology some most effective therapies presently (e.g., glycerol cryoprotectant; inhibitors transport reduce energy demands) effectively mimic strategies natural situation.