Chapter 35 



Biosynthesis of Purine Nucleotides* 



John M. Buchanan 



Division of Biochemistry, Department of Biology 

 Massachusetts Institute of Technology, Cambridge, Massachusetts 



I. Introduction . 304 



II. Precursors of the Purines 304 



III. Enzymic Reactions of Inosinic Acid Synthesis de Novo 306 



IV. Enzymic Synthesis of Formyltetrahydrofolic Acid Compounds 318 



V. Synthesis of Adenylic Acid from Inosinic Acid 319 



VI. Synthesis of Guanylic Acid from Inosinic Acid 320 



VII. Summary 321 



* The following are the systematic names corresponding to the trivial names used 

 in this chapter: 2-amino-A r -ribosylacetamide-5'-phosphate, glycinamide ribonucleo- 

 tide; 2-formamido-V-ribosylacetamide-5'-phosphate, formylglycinamide ribonucleo- 

 tide; 2-formamido-.V-ribosylacetamidine-5'-phosphate, formylglycinamidine 

 ribonucleotide; 5-amino-l-ribosylimidazole-5'-phosphate, 5-aminoimidazole ribo- 

 nucleotide; 5-amino-l-ribosyl-4-imidazolecarboxylic acid 5'-phosphate, 5-amino-4- 

 imidazolecarboxylic acid ribonucleotide; V-(5-amino-l-ribosyl-4-imidazolecarbonyl) - 

 L-aspartic acid 5'-phosphate, 5-amino-4-imidazole-V-succinocarboxamide 

 ribonucleotide; 5-amino-l-ribosyl-4-imidazolecarboxamide-5'-phosphate, 5-amino- 

 4-imidazolecarboxamide ribonucleotide; 5-formamido-l-ribosyl-4-imidazolecarbox- 

 amide-5'-phosphate, 5-formamido-4-imidazolecarboxamide ribonucleotide; 

 [6-(succinylamino)-9-(ribofuranosyl 5'-phosphate) purine], adenylosuccinic acid. 



The following abbreviations have been used: adenosine triphosphate, ATP; 

 adenosine diphosphate, ADP; adenylic acid, AMP; guanosine triphosphate, GTP; 

 guanosine diphosphate, GDP; 5,6,7,8-tetrahydrofolic acid, FH 4 ; orthophosphate, 



Pi ■ 



The number of the atom of the purine ring may be designated as follows : nitrogen 

 atom 1, N-l, carbon atom 2, C-2, etc. 



Since primary emphasis will be placed on the enzymic synthesis of the purine 

 nucleotides, the reader is referred to the chapter on the Biosynthesis of Purines and 

 Pyrimidines by Reichard 1 in Volume II of this book for earlier work on this subject. 

 Also reference may be made to two recent reviews on the synthesis of purine nucleo- 

 tides which treat the subject either in more detailed form or from another point of 

 view. 2 ' 3 



1 P. Reichard, in "The Nucleic Acids" (E. Chargaff and J. N. Davidson, eds.), 

 Vol. II, p. 277. Academic Press, New York, 1955. 



2 S. C. Hartman and J. M. Buchanan, Ergeb. Physiol, u. exptl. Pharmakol. 50, 71 

 (1959). 



3 J. M. Buchanan and S. C. Hartman, Advances in Enzymol. 21, 200 (1959). 



303 



