114 Britton Chance 



its kinetics to those of the 340-m(jL absorption band in 

 response to a variety of chemical treatments. Attempts have 

 been made to see whether a bound form could be obtained in 

 solution, and experiments to date indicate that even slight 



80-1 



/State 4 



I ' I ' I ' I ' I 

 400 420 440 460 480500 



Wavelength (mp) 



580 600; 



Fig. 17. Emission spectrum of fluorescence of 

 mitochondrial suspension excited at 353 mjx. 

 Rat liver mitochondria, p-hydroxybutyrate as 

 substrate. Emission spectrum corrected for 

 transmission of monochromator and sensitivity 

 of photo surface (Expt. no. 777) (From Chance 

 and H. Baltscheffsky, 1958. Reproduced by per- 

 mission of the Editors, J. bioL Chem.) 



damage to the mitochondrial membrane causes disappearance 

 of the fluorescence. 



The existence of this compound, together with the very- 

 high degree of reduction of intramitochondrial pyridine 

 nucleotide in the absence of ADP or phosphate, gives strong 

 support to the hypothesis that the high respiratory control 

 ratio, characteristic of tightly coupled mitochondria utilizing 



