Optimal growth temperature Mesophiles: human body temperature pathogens s opportunists pyschrophile close to freezing thermophile close to boiling
Thermophile and Biotechnology catalyzing biochemical reactions at gh of Enzymes from thermophiles are capable temperature, they are more stable DNA polymerase, Taq polymerase, has been isolated from thermophile- Thermus aquaticus, for PCR application DNA polymerase, pfu polymerase, isolated from hyperthermophile-Pyrocuccus furiosus, is more stable and useful for PCr application, it also less prone to errors Microbial process carried out at high t also eliminate or greatly reduce cooling costs
Thermophile and Biotechnology • Enzymes from thermophiles are capable of catalyzing biochemical reactions at high temperature, they are more stable; • DNA polymerase, Taq polymerase, has been isolated from thermophile-Thermus aquaticus, for PCR application; • DNA polymerase, pfu polymerase, isolated from hyperthermophile-Pyrocuccus furiosus, is more stable and useful for PCR application, it also less prone to errors; • Microbial process carried out at high T also eliminate or greatly reduce cooling costs
Molecular basis for growing at extreme temperatures Molecular adaptations of enzymes to extreme temperatures Cold-active enzymes are more flexible due to higher portion of a helix and less amount of B- sheet Heat resistant enzymes have different folding patterns because of a few different amino acids in some critical positions from their mesophile counterpart, more salt bridges and more densely packed hydrophobic interior
Molecular basis for growing at extreme temperatures • Molecular adaptations of enzymes to extreme temperatures – Cold-active enzymes are more flexible due to higher portion of a helix and less amount of b- sheet – Heat resistant enzymes have different folding patterns because of a few different amino acids in some critical positions from their mesophile counterpart, more salt bridges and more densely packed hydrophobic interior
A-helix provides flexibilit R N CH-N CH-N-H R-CH CH H O CH Hydro gen bonds between nearby amino acids
A-helix provides flexibility
B-sheet causes more rigidity R-C R-c CzO O…H=N RC-A N-Hee OrC R-C R-C R C=O c=o…H=N R R N一H…OEC R H-N cao…H-N C-RC-R C-R Hydrogen bonds oac N一Hoc between distant N一HorC amino acids
B-sheet causes more rigidity