The interaction of granaticin with nucleic acids and pyruvate decarboxylase

The interaction of granaticin with two different yeast ribonucleic acids, dialyzed transfer RNA and calf thymus DNA was studied. Contrary to previous reports, no binding of granaticin to DNA or RNA was observed. The visible spectrum of granaticin on direct mixing or equilibrium dialysis of granaticin with RNA or DNA was unchanged. Furthermore, granaticin did not displace acridine orange from DNA in competitive binding studies using fluorescence polarization. However, granaticin was shown to inhibit pyruvate decarboxylase. From the Ki for granaticin (3.8 mM) it was concluded that granaticin is as efficient as other 1,4-naphthoquinones in inhibiting pyruvate decarboxylase.