TY - JOUR
AU - MINAMIURA,, Noshi
AB - Abstract Phosphodiesterase I [EC 3.1.4.1] was purified from normal human urine in a highly purified state free from phosphodiesterase II, RNase, DNase I, DNase II, and phosphatase by column chromatographies of DEAE-Toyopearl, butyl-Toyopearl, Affi-Gel blue, and Sephadex G-150. The molecular weight of the enzyme was 1.9×105 and the pH optimum around 9.0 with p-nitrophenyl deoxythymidine 5′-phosphate as the substrate. The enzyme hydrolyzed the 3′–5′ linkage of various dinucleoside monophosphates at approximately the same rate and the phosphodiester bonds of cyclic 3′,5′-mononucleotides to produce mononucleoside 5′-phosphate. The enzyme also hydrolyzed ADP to 5′-AMP and P1, ATP to 5′-AMP and PP1, and NAD+ to 5′-AMP and NMN. The enzyme activity was abolished by removal of metal ions with EDTA, and the metal-free enzyme was reactivated on the addition of Zn2+. The enzyme activity was also abolished by some reducing agents and the inhibition was reversed by Zn2+. The metal-free enzyme was less stable than the native enzyme, and Zn2+ and Co2+ restored the stability of the metal-free enzyme to the level of the native enzyme. The enzyme degraded oligonucleotides and high molecular nucleotides stepwise from the 3′-termini to give 5′-mononucleotides. The enzyme hydrolyzed single-stranded DNA more preferentially than double-stranded DNA. The enzyme also nicked superhelical covalently closed circular φX174 DNA to yield first open circular DNA and then linear DNA. This content is only available as a PDF. © The Journal of Biochemistry
TI - Phosphodiesterase I in Human Urine: Purification and Characterization of the Enzyme
JO - The Journal of Biochemistry
DO - 10.1093/oxfordjournals.jbchem.a122062
DA - 1987-08-01
UR - https://www.deepdyve.com/lp/oxford-university-press/phosphodiesterase-i-in-human-urine-purification-and-characterization-W9JaM4ef6p
SP - 359
EP - 367
VL - 102
IS - 2
DP - DeepDyve
ER -