title: Efficient single-strand cleavage of DNA mediated by a MnIIIMnIV-based artificial nuclease.
abstract: A water-soluble Mn(IV) 1,4,7-triazacyclononane complex, [Mn(IV)2L2(μ-O)2](ClO4)2·2H2O (1), was prepared to serve as a nuclease mimic (L = 1,4,7-triazacyclononane-N-acetate). Complex 1 was readily synthesized from the highly water soluble ligand (L), with Mn(III) salt, [Mn3O(MeCO2)7]·3H2O in basic condition, and characterized by X-ray, IR, electronic spectroscopy, cyclic voltammetry and magnetic susceptibility as well as ESI-MS. The bond valence sum (BVS) analysis and magnetic data suggest that 1 is a Mn(IV)-μ-O2-Mn(IV) species. The electrospray mass spectrum and electronic spectrum of 1 in aqueous solution indicates that dinuclear Mn complex [Mn(III)Mn(IV)L2(μ-O)2](+) (2) is the active species. A predominantly hydrolytic cleavage mechanism was confirmed through experiments performed in the presence of various radical scavengers, T4 ligase and under anaerobic conditions. The kinetic aspects of DNA cleavage under pseudo- or true-Michaelis-Menten conditions were also detailed, kinetic parameters (kcat, KM, Vmax) were calculated to be 6.27 h(-1), 7.35 × 10(-5) M, 4.6 × 10(-4) M h(-1); 0.683 h(-1), 1.93 × 10(-5) M, 1.32 × 10(-5) M h(-1) for 2, respectively.
authors: College of Chemistry, Tianjin Normal University, 300387, Tianjin, P. R. China. qianjinger@aliyun.com.
authors: Jing
authors: J
authors: Qian
authors: Shasha
authors: S
authors: Yu
authors: Wenjun
authors: W
authors: Wang
authors: Liping
authors: L
authors: Wang
authors: Jinlei
authors: J
authors: Tian
authors: Shiping
authors: S
authors: Yan
mesh_terms: D000818:Animals; D040761:Biomimetic Materials / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D002417:Cattle; D018360:Crystallography, X-Ray; D053837:DNA Cleavage / Q000187:drug effects*; D011088:DNA Ligases / Q000378:metabolism; D004277:DNA, Single-Stranded / Q000737:chemistry*; D003851:Deoxyribonucleases / Q000378:metabolism*; D016166:Free Radical Scavengers / Q000494:pharmacology; D007700:Kinetics; D060328:Magnetic Phenomena; D008345:Manganese / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D009942:Organometallic Compounds / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D010957:Plasmids / Q000235:genetics; D012710:Serum Albumin, Bovine / Q000378:metabolism
chemical_list: D004277:DNA, Single-Stranded; D016166:Free Radical Scavengers; D009942:Organometallic Compounds; D012710:Serum Albumin, Bovine; D008345:Manganese; D003851:Deoxyribonucleases; D011088:DNA Ligases