title: [Hybridase cleavage of RNA. III. Use of UV-spectroscopy for studying the kinetic properties of E. coli RNAase properties].
abstract: A one-step procedure for estimating the activity of ribonuclease H from E. coli has been developed. This method is based on continuous registration of the increment in the UV adsorption of the substrate in the course of the enzymatic reaction. The heteroduplex Am.dT20 (m = 18-24) was found to be the optimal substrate for the enzyme. A comparative analysis of the rates of the enzymatic reaction as determined by UV spectroscopy and ion-pair HPLC was carried out. The kinetic parameters of the Am hydrolysis in Am.dT20 catalyzed by E. coli RNase have been determined for the first time (Km = 44 +/- 11 nM, Vmax = 0.0363 +/- 0.0053 E). The method sensitivity is 0.01-0.05 E which makes it possible to determine the RNAse H within the concentration range of 0.5-2.5 u./ml.
authors.forename: N F
authors.initials: NF
authors.lastname: Krynetskaia
authors.forename: V N
authors.initials: VN
authors.lastname: Tashlitskiĭ
authors.forename: V M
authors.initials: VM
authors.lastname: Belkov
authors.forename: V G
authors.initials: VG
authors.lastname: Metelev
authors.forename: Z A
authors.initials: ZA
authors.lastname: Shabarova
mesh_terms: D002851:Chromatography, High Pressure Liquid; D004926:Escherichia coli / Q000201:enzymology*; D006868:Hydrolysis; D007700:Kinetics; D009693:Nucleic Acid Hybridization; D012329:RNA, Bacterial / Q000378:metabolism*; D016914:Ribonuclease H / Q000378:metabolism*; D013056:Spectrophotometry, Ultraviolet; D013379:Substrate Specificity
chemical_list: D012329:RNA, Bacterial; D016914:Ribonuclease H
vernacular_title: Gibridaznoe rasshcheplenie RNK. III. Ispol'zovanie UF-spektroskopii dlia izucheniia kineticheskikh svoĭstv RNKazy N iz E. coli.