Adenosine triphosphate-nicotinamide mononucleotide adenylyltransferase of pig-liver nuclei. Extraction and purification of the enzyme

Abstract

Conditions for the extrac-tion of adenosine triphosphate-nicotinamide mononucleotide adenyl-yltransferase from pig-liver nuclei have been described. Extracts that contained the adenylyltransferase also contained nucleic acid. Adenylyltransferase that would form 2-3[mu]-moles of nicotinamide-adenine dinucleotide/min./mg. of protein was obtained by adsorption on calcium phosphate, fractionation with ammonium sulphate, chromatography on ion-exchange cellulose and fractionation with acetone. The final product had an E280 m[mu]/E260 m[mu] ration of 1[center dot]5-1[center dot]6. After electrophoresis in starch gel at least three zones with adenylyltransferase activity were detected in a coupled assay with nicotinamide mononucleotide, adenosine triphosphate, magnesium chloride, ethanol, alcohol dehydrogenase, diaphorase and nitroblue tetrazolium. Inactive protein was found in the purest preparations of the adenylyltransferase.