Electrochemical assay for deoxyribonuclease I activity.
A thiolated oligonucleotide having three ferrocenes was immobilized on a gold electrode through the sulfur-gold linkage. This electrode showed a current response based on the redox reaction of the ferrocene moieties and this response was decreased after treatment with deoxyribonuclease I (DNase I), suggesting the disappearance of the ferrocene moieties on the electrode by the DNase I digestion. A linear correlation between i(0) and i, which are current peaks before and after DNase I treatment, respectively, was observed and this slope was decreased with increase in the amount of DNase I. No current decrease was observed in the presence of EDTA or RNase A instead of DNase I. These results suggested that the current decrease responded specifically to the amount of DNase I and this electrode could be used for an electrochemical DNase I assay. Under the optimum conditions of DNase I digestion at 37 degrees C for 30 min, a quantitative analysis could be achieved in the range of 10(-4)-10(-2)units/microl of DNase I.
Sato
Shinobu
S
Department of Applied Chemistry, Faculty of Engineering, Kyushu Institute of Technology, Kitakyushu, Fukuoka 804-8550, Japan.
Fujita
Katsuya
K
Kanazawa
Masanori
M
Mukumoto
Kosuke
K
Ohtsuka
Keiichi
K
Waki
Michinori
M
Takenaka
Shigeori
S
D002234:Carbodiimides / Q000737:chemistry; D003850:Deoxyribonuclease I / Q000032:analysis* / Q000378:metabolism; D004563:Electrochemistry / Q000295:instrumentation / Q000379:methods*; D004566:Electrodes; D005296:Ferrous Compounds / Q000737:chemistry*; D000075163:Metallocenes; D009841:Oligonucleotides / Q000737:chemistry; D010084:Oxidation-Reduction; D013873:Thionucleotides / Q000737:chemistry
D002234:Carbodiimides; D005296:Ferrous Compounds; D000075163:Metallocenes; D009841:Oligonucleotides; D013873:Thionucleotides; D003850:Deoxyribonuclease I; C004998:ferrocene