Theoretical study of antagonists and inhibitors of mammalian adenosine deaminase: I. Adenosine and its aza- and deazaanalogues

Aza- and deazaanalogues of adenosine, including their 1-protonated forms (except for that of 1-deazaadenosine), were studied by computer computation to find a relationship between their molecular structures and substrate properties for the mammalian adenosine deaminase. The atomic charge distribution and maps of the electrostatic potential around their van der Waals molecular surface were calculated for these compounds using the ab initio STO-3G method. The conformational studies are carried out by the MM+ method of molecular mechanics. The mechanism that determines the substrate selectivity of mammalian adenosine deaminase is discussed.