Abstract

Molecular dynamics play a key role in determining and predicting the efficacy of transition metal magnetic resonance imaging (MRI) contrast agents. We have used EPR and nuclear magnetic relaxation dispersion (NMRD) data on dendrimer-bound and free metal chelate complexes with VO2+ and TEMPOL to obtain precise dynamical information, as well as provide an expanded data base of paramagnetic center/proton relaxation. Both the NMRD and EPR data are consistent with a significant increase in the rotational correlation time on binding chelate to dendrimeric polymer. The NMRD profiles show a peak in the high-field region (6-60 MHz proton Larmor frequency), consistent with increasing ?r??s. Correlation times of 0.7 < ?r < 2.7 ns are measured by EPR over physiological temperatures, which are much larger than 0.1 ns as predicted by other authors. These results confirm qualitatively the predictions of the Solomon-Bloembergen-Morgan (SBM) theory, and provide an excellent platform from which to expan d our understanding of motional effects on contrast agent-proton relaxation. The first major results of this study were published last year. Work continues, with anisotropic motion a focus of new work.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Center for Research Resources (NCRR)
Type
Biotechnology Resource Grants (P41)
Project #
5P41RR001811-13
Application #
6120609
Study Section
Project Start
1998-04-15
Project End
1999-11-30
Budget Start
1997-10-01
Budget End
1998-09-30
Support Year
13
Fiscal Year
1998
Total Cost
Indirect Cost

  Institution

Name
University of Illinois at Chicago
Department
Type
DUNS #
121911077
City
Chicago
State
IL
Country
United States
Zip Code
60612

  Publications

Hurth, Kyle M; Nilges, Mark J; Carlson, Kathryn E et al. (2004) Ligand-induced changes in estrogen receptor conformation as measured by site-directed spin labeling. Biochemistry 43:1891-907
Woodmansee, Anh N; Imlay, James A (2002) Reduced flavins promote oxidative DNA damage in non-respiring Escherichia coli by delivering electrons to intracellular free iron. J Biol Chem 277:34055-66
Denisov, Ilia G; Makris, Thomas M; Sligar, Stephen G (2002) Formation and decay of hydroperoxo-ferric heme complex in horseradish peroxidase studied by cryoradiolysis. J Biol Chem 277:42706-10
Atsarkin, V A; Demidov, V V; Vasneva, G A et al. (2001) Mechanism of oxygen response in carbon-based sensors. J Magn Reson 149:85-9
Mangels, M L; Harper, A C; Smirnov, A I et al. (2001) Investigating magnetically aligned phospholipid bilayers with EPR spectroscopy at 94 GHz. J Magn Reson 151:253-9
Breitzer, J G; Smirnov, A I; Szczepura, L F et al. (2001) Redox properties of C6S8(n-) and C3S5(n-) (n = 0, 1, 2): stable radicals and unusual structural properties for C-S-S-C bonds. Inorg Chem 40:1421-9
Denisov, I G; Hung, S C; Weiss, K E et al. (2001) Characterization of the oxygenated intermediate of the thermophilic cytochrome P450 CYP119. J Inorg Biochem 87:215-26
Kirkor, E S; Scheeline, A (2000) Nicotinamide adenine dinucleotide species in the horseradish peroxidase-oxidase oscillator. Eur J Biochem 267:5014-22
Rapoport, N; Smirnov, A I; Pitt, W G et al. (1999) Bioreduction of Tempone and spin-labeled gentamicin by gram-negative bacteria: kinetics and effect of ultrasound. Arch Biochem Biophys 362:233-41
Maringanti, S; Imlay, J A (1999) An intracellular iron chelator pleiotropically suppresses enzymatic and growth defects of superoxide dismutase-deficient Escherichia coli. J Bacteriol 181:3792-802

Showing the most recent 10 out of 16 publications