Pfizer Handbook of Microbial Metabolites 524 



Calvin L. Stevens, Robert J. Gasser, Tapan K. Mukherjee 

 and Theodore H. HaskeU, ibid. 78 6212 (1956). 



n. PURINES 



The nature of nucleic acids and the participation of 

 purines in their structure were discussed in the preceding 

 section. The process of oxidative phosphorylation also 

 was mentioned although it is not yet entirely understood. 

 In this process inorganic phosphate ions disappear dur- 

 ing biological oxidation of substrates and become bound 

 in adenosine triphosphate (ATP), the universal storage 

 molecule for chemical energy wdthin cells. Many ex- 

 amples of ATP as an energy donor were seen in earlier 

 sections. 



Adenosine polyphosphates have other functions, most 

 of them concerned with the activation and transfer of 

 various chemical moieties with formation of new chemi- 

 cal bonds. ATP, for example, can donate phosphate or 

 pyrophosphate groups to form new phosphate esters. 

 Two such known reactions are: 



hexokinase 

 Glucose + ATP ;===^ Glucose-6-phosphate + ADP 



M^ 

 and phosphoribose 



pyrophosphokinase 

 Ribose-5-phosphate -H ATP ^ ^ri Ribose-5-phosphate-l- 



pyrophosphate + AMP 



Adenosine-3'-phospho-5'-phosphosulfate has been estab- 

 Ushed as activated sulfate,^- - and it has been used in the 

 formation of sulfate esters of a number of phenols and 



^ Robert S. Bandurski, Lloyd G. Wilson and Craig L. Squires, 

 /. Am. Chem. Soc. 78 6408 (1956). 



2 P. W. Robbins and Fritz Lipmann, ibid. 78 2652, 6409 (1956). 



