Carboxylate binding in copper histidine complexes in solution and in zeolite Y: X- and W-band pulsed EPR/ENDOR combined with DFT calculations

被引:61
作者
Baute, D
Arieli, D
Neese, F
Zimmermann, H
Weckhuysen, BM
Goldfarb, D [1 ]
机构
[1] Weizmann Inst Sci, Dept Phys Chem, Rehovot, Israel
[2] Max Planck Inst Med Res, Heidelberg, Germany
[3] Max Planck Inst Bioinorgan Chem, Mulheim, Germany
[4] Univ Utrecht, Dept Inorgan Chem & Catalysis, Utrecht, Netherlands
关键词
D O I
10.1021/ja047761c
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
The complexes of copper with histidine exhibit a wide variety of coordination modes in aqueous solution. This stems from the three potential coordination sites of the histidine molecule and the existence of mono- and bis-complexes. The present work concentrates on the determination of the carboxylate binding mode, via the (13)C hyperfine coupling of the carboxyl, in a number of copper complexes in frozen solutions. These are then used as references for the determination of the coordination mode of two zeolite encapsulated complexes. The (13)C hyperfine coupling (sign and magnitude) was determined by a variety of advanced pulsed EPR and electron-nuclear double resonance (ENDOR) techniques carried out at conventional and high magnetic fields. These showed that while the carboxyl (13)C isotropic hyperfine coupling of an equatorially coordinated carboxylate is negative with a magnitude of 3-4 MHz, that of a free carboxylate is small (similar to1 MHz) and positive. To rationalize the experimentally determined ligand hyperfine couplings ((1)H and (13)C) and further understand their dependence on the coordination mode and degree of protonation, density functional theory (DFT) calculations were carried out on a number of model complexes, representing the different Cu-histidine complexes studied experimentally. The exchange-correlation functional used for the calculation of the EPR parameters was B(3)LYP with triple-xi plus polarization (TZP) quality basis sets. While the polarization agreement between the magnitudes of the calculated and experimental values varied among the various nuclei, sometimes exhibiting deviations of up to 40%, an excellent agreement was found for the sign prediction. This shows the unique advantage of combining high field ENDOR, by which the sign of the hyperfine can often be determined, with DFT predictions for structure determination.
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页码:11733 / 11745
页数:13
相关论文
共 81 条
[31]  
Koch W. H. M. C., 2015, A Chemist's Guide to Density Functional Theory
[32]   Two-dimensional pulsed EPR spectroscopy of the copper protein azurin [J].
Kofman, V ;
Farver, O ;
Pecht, I ;
Goldfarb, D .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1996, 118 (05) :1201-1206
[33]   Density functional theory of electronic structure [J].
Kohn, W ;
Becke, AD ;
Parr, RG .
JOURNAL OF PHYSICAL CHEMISTRY, 1996, 100 (31) :12974-12980
[34]  
KURRECK H, 1988, ELECT NUCL DOUBLE RE, pCH3
[35]   DFT calculations of proton hyperfine coupling constants for [VO(H2O)5]2+:: Comparison with proton ENDOR data [J].
Larsen, SC .
JOURNAL OF PHYSICAL CHEMISTRY A, 2001, 105 (36) :8333-8338
[36]   DEVELOPMENT OF THE COLLE-SALVETTI CORRELATION-ENERGY FORMULA INTO A FUNCTIONAL OF THE ELECTRON-DENSITY [J].
LEE, CT ;
YANG, WT ;
PARR, RG .
PHYSICAL REVIEW B, 1988, 37 (02) :785-789
[37]  
Lontie R., 1984, COPPER PROTEINS COPP, Vvol. I- III
[38]   Density functional calculations of electronic g-tensors using spin-orbit pseudopotentials and mean-field all-electron spin-orbit operators [J].
Malkina, OL ;
Vaara, J ;
Schimmelpfennig, B ;
Munzarová, M ;
Malkin, VG ;
Kaupp, M .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 2000, 122 (38) :9206-9218
[39]   Structure of copper(II) -histidine based complexes in frozen aqueous solutions as determined from high-field pulsed electron nuclear double resonance [J].
Manikandan, P ;
Epel, B ;
Goldfarb, D .
INORGANIC CHEMISTRY, 2001, 40 (04) :781-787
[40]   PULSED ENDOR EXPERIMENTS [J].
MIMS, WB .
PROCEEDINGS OF THE ROYAL SOCIETY OF LONDON SERIES A-MATHEMATICAL AND PHYSICAL SCIENCES, 1965, 283 (1395) :452-&