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F. M. HUENNEKENS AND H. R. WHITELEY
5'-triphosphate (ATP), followed to a lesser extent by adenosine-5'-diphosphate (ADP) and the recently discovered adenosine-5
/
-tetraphosphate. We shall also include in the discussion, although briefly, the
polyphosphates of other nucleosides: guanosine, inosine, cytidine, and
uridine. The structures of these compounds are shown in Fig. 4.
I. Adenosine Polyphosphates
«
.^
^5
HCHCOH
i
0
HCOH
HC—-Ό
0 , 0
I
II
II
II
CH2-P-0-P-(j>-P-0H
OH OH' OH
-ADP
H
-ATPII. Other Nucleoside Polyphosphates
A. Guanosine Polyphosphates
I, Base =
B. Inosine Polyphosphates
C. Cytidine Polyphosphates
OH
0. Uridine Polyphosphates
FIG. 4. Structures of nucleoside polyphosphates.
The nucleoside polyphosphates are found in a wide variety of cells
and tissues and it is evident that the prototype, ATP, is the primary
phosphorylating agent for most enzymatic reactions (50), and hence,