Chemical-Kinetic Studies of the Hill Reaction* 



RUFUS LUMRY and JOHN D. SPIKES, Division of Physical 

 Chemistry, Institute of Technology, University of Minnesota, Minne- 

 apolis, Minnesota, and De-partment of Experimental Biology, University 



of Utah, Salt Lake City, Utah 



INTRODUCTION 



We have continued the hne of investigation reported at the first 

 GatHnburg conference in an attempt to secure a higher-plant chloro- 

 plast system suitable for precise and definitive measurements of 

 chemical kinetics of the Hill reaction. Most biological systems, in- 

 cluding those able to carry out photosynthesis, are usually so diffi- 

 cult to control as to make kinetic studies with them a rather hit-or- 

 miss affair. Initial experiments suggested that chloroplast fragments 

 from higher plants might prove simple enough to allow control at the 

 level found necessary for a fundamental understanding of the chemis- 

 try of simpler systems and now affording such rapid progress in 

 protein and enzyme investigation. To judge from the history of 

 chemistry, precise kinetic investigations will have to be coupled with 

 extensive biochemistry if we are ever to understand the mechanism 

 of photosynthesis at more than a superficial level. 



It cannot yet be said with absolute confidence that chloroplast 

 fragments will provide an ideal system but our elTorts to date support 

 our early optimism, ^^'e would like to report ]:)riefly the progress in 

 control studies as well as some observations about the kinetic patterns 

 which are developing. 



* This work was supported by grants from the U. S. Atomic Energy Com- 

 mission and the Research Fund of the University of Utah. The original work dis- 

 cussed here, both published and unpubUshed, was obtained by a cooperative 

 research group at the University of Utah which has at one time or another in- 

 cluded D. Anderson, N. Bishop, B. Burnham, H. Eyring, H. Gilmour, R. Lumry, 

 R. Marcus, B. Mayne, Wanda H. Rice, J. Rieske, J. D. Spikes, and R. Wayrynen. 

 This Ust should be supplemented by the names of a nimil)er of skillful and helpful 

 technical assistants including Bonnie Jean Slater, Prima Boyer, Fumi Fujii, and 

 Beverly Sandmann. The preparation of this manu.script was aided by a grant 

 from the Xationul Science Foundation. 



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