PBOSSER 



I should say in respect to the mechanisms of acclimation that 

 there has been some indication that one can change the tempera- 

 tures of inactivation of enzymes. The prize example of this is in 

 the thermophilic bacteria, where Koffler* and others have shown 

 that the cytochromes function at temperatures up to 70 C, where- 

 as the corresponding proteins from mesophils are knocked out at 

 35 G. This is a fantastic difference. It must mean that there is a 

 difference in tertiary structure in the same enzyme protein. 



HART: I wanted to ask you aboutthose curves which you showed 

 of activity metabolism versus temperature — was it for the green 

 sunfish, which is a different species, or was it for the goldfish you 

 showed? 



PROSSER; The activity curve that I showed you was for the 

 green sunfish. Your curves have been for goldfish and they were 

 smaller goldfish than we used. We have not been able to get such 

 complete curves for the goldfish; that was the reason I did not 

 show you goldfish data. We have some curves, but for some rea- 

 son we have not had as good luck getting complete swimming 

 curves for them as for the green sunfish. 



HART: Those are beautiful curves. These curves agree with 

 the general concept that Fry developed, which is that the activity 

 would be determined by the difference between standard and active 

 metabolism. 



PROSSER: Yes, I think that is so. 



HART: I wondered if you had any data on the resting versus 

 active metabolism to compare with those active metabolism data? 



PROSSER: Not for the green sunfish. 



HART: Does this conflict with Fry's concept? 



♦Koffler, H. 1957. Enzyme of thermal bacteria. Bacteriol. Rev. 21:227-240. 



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