Catalytic promiscuity: catecholase-like activity and hydrolytic DNA cleavage promoted by a mixed-valence FeIII FeII complex

Abstract

Os estudos sobre enzimas têm mostrado que existe uma relação clara entre a evolução enzimática e a propriedade de promiscuidade catalítica que elas podem apresentar. Com isto, o desenvolvimento de sistemas biomiméticos capazes de atuar de modo promíscuo, de forma similar a algumas enzimas, mostrou-se um novo desafio para os químicos bioinorgânicos. Neste trabalho, reportamos a estrutura de raios X e os estudos em solução e de promiscuidade catalítica do complexo [(bpbpmp)Fe . Assim, o complexo 1 apresenta atividades de hidrolase e oxidoredutase, sendo um interessante modelo sintético para estudos de promiscuidade catalítica.Catalytic promiscuity has emerged as an important property of many enzymes since the relationship of this property to enzymatic evolution became clear. Simultaneously, the development of suitable biomimetic catalytic systems capable of mimicking the promiscuous catalytic properties of such enzymes represents a new challenge for bioinorganic chemists. In this paper we report on the X-ray structure, the solution studies and the promiscuous catalytic activity of the mixed-valence complex [(bpbpmp)Fe III (m-OAc) 2 Fe II ](ClO 4 ), (1), containing the unsymmetrical dinucleating ligand 2-{[(2-hydroxybenzyl)(2-pyridylmethyl)aminomethyl]-4-methyl-6-[bis(2-pyridylmethyl) aminomethyl]}phenol (H 2 bpbpmp). Potentiometric and spectrophotometric titrations and kinetics studies showed that this coordination compound generates active species that promote hydrolytic cleavage of double strand DNA (dsDNA), with a rate enhancement of 1.9×10 8 over the non-catalyzed reaction, as well as promote oxidation of 3,5-di-tert-butylcatechol (3,5-dtbc), with k cat = 1.16 × 10 -2 s -1and K M = 7.1×10 -4 mol L -1. Thus, complex 1 shows both hydrolase and oxidoreductase activities and can be regarded as a man-made model for studying catalytic promiscuity.

Synthesis, structure, magnetism, and hydrolase and catecholase activity of a new trinuclear copper(II) complex

“…NHE can be attributed to the couples Cu 2 II Cu I /Cu II Cu 2 I and Cu II Cu 2 I /3Cu 3 I , respectively. In fact, these values are in good agreement with the reduction potentials observed for dinuclear copper(II) complexes containing a l-alkoxo bridge and phenolate/pyridine ligands [7,9,10]. The electronic spectrum of 1 (Fig.…”

“…While several enzymes displaying catalytic promiscuity have been the subject of recently reported investigations [6], there are few examples of synthetic analogues which exhibit such multifunctional activities [7][8][9][10][11].…”

DNA binding, cleavage and cytotoxicity of a novel dimetallic Fe(III) triaza-cyclononane complex

“…From the Lineweaver-Burk plot, the hydrolysis rate of the bound substrate, k cat = 3.56 Â 10 À4 s À1 , and the substrate binding constant, K m = 0.56 mM, were obtained. These values indicate a good catalytic activity and a moderate binding affinity of BDNPP for 2 and are in line with other dinuclear Fe(III) complexes reported in the literature [29][30][31]. Based on the kinetic data we propose the mechanism shown in Chart 3 for the hydrolysis of BDNPP by 2.…”

“…As shown in Fig. S4, no [28], but a few examples of Ferric complexes that hydrolyze DNA have been reported as well [29][30][31][32]. Therefore, we thought it of interest to explore the potential of 2 to mediate phosphate ester hydrolysis using BDNPP (bis(2,4-dinitrophenyl) phosphate) which is a widely used model for the phosphodiester linkages in DNA.…”

CATALASE, CATECHOLASE AND PHENOXAZINONE SYNTHASE-LIKE ACTIVITIES OF HOMODINUCLEAR Co(II), Ni(II), Cu(II) and Zn(II) COMPLEXES INCLUDING OXIME GROUP

“…27 Neves et al studied dinuclear mixed valence Fe(III) and Fe(II) complex and obtained higher k obs values (0.696 min -1 ) compared to our results (0.143 min -1 for Cu(II)). 28 The reaction mechanism for catecholase described below in three steps starts with the bonding of 3,5-DTBC with dinuclear complex releasing two hydrogens. In this step, Cu(II) ions of the complex are reduced to Cu(I).…”