Field dependent dynamic nuclear polarization with radicals in aqueous solution

被引：111

作者：

Hoefer, Peter ^{[2
]}

Parigi, Giacomo ^{[3
]}

Luchinat, Claudio ^{[3
]}

Carl, Patrick ^{[2
]}

Guthausen, Gisela ^{[2
]}

Reese, Marcel ^{[1
]}

Carlomagno, Teresa ^{[1
]}

Griesinger, Christian ^{[1
]}

Bennati, Marina ^{[1
]}

机构：

[1] Max Planck Inst Biophys Chem, Gottingen, Germany

[2] Bruker Biospin, EPR Div, Rheinstetten, Germany

[3] Univ Florence, CERM, Sesto Fiorentino, Italy

来源：

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY | 2008年 / 130卷 / 11期

关键词：

D O I：

10.1021/ja0783207

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

The dynamic nuclear polarization (DNP) effect between the polarizers TEMPOL and trityl and the H-1 protons of water solution was investigated at two different magnetic fields corresponding to electron pumping frequencies of 9 and 94 GHz. For TEMPOL, large DNP enhancements up to about -100 (9 GHz) and -20 (94 GHz) were observed by continuous microwave irradiation on one of the three nitroxide hyperfine lines. These enhancements are considerably larger than those ever reported for this system and also larger than the ones we obtained with the second proposed polarizer agent, the trityl radical, under the same conditions. H-1 Overhauser coupling factors were extracted from NMRD relaxation dispersion experiments and used to estimate the degree of effective saturation of the TEMPOL EPR line. Our results show that nitroxide radicals are well-suited polarizers for DNP experiments in aqueous solutions at variable fields. The large enhancements open up attractive perspectives for the application potential of DNP in solution NMR with macromolecular complexes.

引用

页码：3254 / +

页数：3

共 17 条

[1] EPR and DNP properties of certain novel single electron contrast agents intended for oximetric imaging [J].