VOL. 12 (1953) BIOCHIMICA ET BIOPHYSICA ACTA 121 



HEAT OF HYDROLYSIS OF TRIMETAPHOSPHATE* 



by 



OTTO MEYERHOF**, ROMAS SHATAS*** and ANN KAPLAN 



Department of Physiological Chemistry, School of Medicine, 

 University of Pennsylvania, Philadelphia, Pa. {U.S.A.)^ 



INTRODUCTION 



Although the occurrence of metaphosphate in yeast was discovered some sixty 

 years ago by Liebermann^ and later by Kossel^ more extensive investigations about 

 its biochemical significance have been undertaken only in the past fifteen years. In 1928, 

 Kitasato demonstrated the presence of metaphosphatase in enzyme extracts^. In 1936, 

 MacFarlane found metaphosphate in a nucleic acid preparation of yeast^ and later 

 Mann isolated metaphosphate from Aspergillus niger^. The same year Jeener and 

 Bracket observed that by a preceding period of starvation, the absorption of ortho- 

 phosphate by yeast was greatly enhanced^. Simultaneously, a basophilic substance was 

 synthetized which was identified as metaphosphate by Wiame'', and Schmidt, Hecht 

 AND Thannhauser^. Wiame demonstrated employing a staining technique based on the 

 metachromatic reaction^ that a substance called volution, closely related with the pro- 

 cesses of cell division, contained metaphosphate^*'. Later, Lindegren suggested the 

 hypothesis that the "high energy" bond of metaphosphate could be used by the cell to 

 synthetize nucleoproteins during the mitosis^^. However, the role of metaphosphate in 

 catabolism is far from completely understood^^- ^^. 



The clarification of energetic relations has contributed much to the rapid progress 

 in the elucidation of phosphorus metabolism in the past. Likewise, knowledge of these 

 relations would be of great help in devising a scheme to incorporate both the synthesis 

 and the catabolic utilization of metaphosphate into the general picture of phosphorus 

 metabolism^*. These reasons induced us to study quantitatively the P-O-P bond energy 

 of metaphosphate^. 



Several different experimental approaches are possible to obtain the thermodynamic 

 data necessary to calculate the change in free energy. The first one is based upon the 

 determination of the equilibrium constant, K, in accordance with the equation 



— AF = RT InK. 



* This paper is based on investigations supported by grants from The American Cancer Society 

 (recommended by the Committee on Growth of the National Research Council) and the U.S. Public 

 Health Service. 



** Deceased: October 6, 1951. 



*** Physicist, Bartol Research Foundation of The Franklin Institute, Swarthmore, Pennsylvania. 



t One of the authors (R. S.) wishes to express his gratitude to The Bartol Research Foundation 

 of The Franklin Institute for allowing him to use the facilities of the Foundation during the writing 

 of this paper. 



§ Due to the discontinuance of the laboratory of the principal investigator (Otto Meyerhof) 

 after his death, the experiments on other condensates of orthophosphoric acid were interrupted. 



References p. i2y. 



