Mung bean nuelease: mode of action and specificity vs synthetic esters of 3′-nucleotides

• Published in: Nucleic acids research 1974-05, Vol.1 (5), p.699-706
• Main Authors: Kole, R., Sierakowska, Halina, Szemplińska, Halina, Shugar, D.
• Format: Article
• Language: English
• ISSN: 0305-1048; 1362-4962
• DOI: 10.1093/nar/1.5.699

Hung bean nuolease hydrolyzes synthetic esters of 3′-nucleotides to nucleosides and phosphate esters; esters of 2′-nucleotides, and 2′→5′ internucleotide linkages, are resistant. Esters of ribonucleotides are cleaved at 100-fold the rate for deoxyribonucleotides, the increased rate being due to presence of the 2′-hydroxyl and not to differences in conformation. Introduction of a 5′-substituent leads to a 3-fold increase in rate. The rates of hydrolysis vary up to 10-fold with the nature of the base, in the order adenine > hypoxanthine > uracil; and up to 6-fold with the nature of the ester radical. This form of cleavage of esters of 3′-nucleotides is also characteristic for nuclease-3′-nucleotidase activities from potato tubers and wheat, suggesting that one type of enzyme is responsible for all these activities.