A new heterobinuclear FeIIICuII complex with a single terminal FeIII-O(phenolate) bond. Relevance to purple acid phosphatases and nucleases.
A novel heterobinuclear mixed valence complex [Fe(III)Cu(II)(BPBPMP)(OAc)(2)]ClO(4), 1, with the unsymmetrical N(5)O(2) donor ligand 2-bis[{(2-pyridylmethyl)aminomethyl}-6-{(2-hydroxybenzyl)(2-pyridylmethyl)}aminomethyl]-4-methylphenol (H(2)BPBPMP) has been synthesized and characterized. A combination of data from mass spectrometry, potentiometric titrations, X-ray absorption and electron paramagnetic resonance spectroscopy, as well as kinetics measurements indicates that in ethanol/water solutions an [Fe(III)-(mu)OH-Cu(II)OH(2)](+) species is generated which is the likely catalyst for 2,4-bis(dinitrophenyl)phosphate and DNA hydrolysis. Insofar as the data are consistent with the presence of an Fe(III)-bound hydroxide acting as a nucleophile during catalysis, 1 presents a suitable mimic for the hydrolytic enzyme purple acid phosphatase. Notably, 1 is significantly more reactive than its isostructural homologues with different metal composition (Fe(III)M(II), where M(II) is Zn(II), Mn(II), Ni(II), or Fe(II)). Of particular interest is the observation that cleavage of double-stranded plasmid DNA occurs even at very low concentrations of 1 (2.5 microM), under physiological conditions (optimum pH of 7.0), with a rate enhancement of 2.7 x 10(7) over the uncatalyzed reaction. Thus, 1 is one of the most effective model complexes to date, mimicking the function of nucleases.
Lanznaster
Mauricio
M
LABINC Laboratório de Bioinorgânica e Cristalografia, Departamento de Química, Universidade Federal de Santa Catarina, Campus Trindade, 88040-900 Florianópolis, SC, Brazil.
Neves
Ademir
A
Bortoluzzi
Adailton J
AJ
Aires
Veronika V E
VV
Szpoganicz
Bruno
B
Terenzi
Hernán
H
Severino
Patricia Cardoso
PC
Fuller
Julie M
JM
Drew
Simon C
SC
Gahan
Lawrence R
LR
Hanson
Graeme R
GR
Riley
Mark J
MJ
Schenk
Gerhard
G
D000135:Acid Phosphatase / Q000737:chemistry*; D002384:Catalysis; D003300:Copper / Q000737:chemistry; D003851:Deoxyribonucleases / Q000737:chemistry*; D006023:Glycoproteins / Q000737:chemistry*; D007501:Iron / Q000737:chemistry; D008958:Models, Molecular; D009942:Organometallic Compounds / Q000737:chemistry
D006023:Glycoproteins; D009942:Organometallic Compounds; D003300:Copper; D007501:Iron; D003851:Deoxyribonucleases; C091137:purple acid phosphatase; D000135:Acid Phosphatase