. "Any process that modulates the frequency, rate or extent of purine nucleotide biosynthetic processes." . . . "regulation of purine nucleotide biosynthetic process" . "regulation of purine nucleotide anabolism" . "regulation of purine nucleotide biosynthesis" . "regulation of purine nucleotide formation" . "regulation of purine nucleotide synthesis" . . . . . . . . . . . . . .