We have presented a model for analyzing polarization transfer via the thermal mixing dynamic nuclear polarization (DNP) mechanism at high magnetic field strengths that accounts for electron-electron cross-relaxation within an inhomogeneously broadened EPR line and have applied this model to simulate DNP and ELDOR experiments in the 4-amino TEMPO/water/glycerol system. These studies indicate that the 40 mM 4-amino TEMPO EPR line is in the intermediate cross-relaxation regime. Thus, the three-bath thermal mixing model, used previously to describe low field experiments, does not adequately explain the.polarization dynamics of the system at high fields. Given some basic parameters, such as the EPR line shape and spinlattice relaxation times, the model developed here can be used to predict the efficiency of DNP at even higher magnetic field strengths, where thermal mixing will be more severely attenuated due to the greater spectral dispersion and hence slower cross-relax ation rate , and with polarization agents other than the 4-amino TEMPO radical. Using this approach, it may be possible to develop optimal paramagnetic systems for performing DNP under experimental conditions suited for solid-state NMR studies of biological samples.

Agency
National Institute of Health (NIH)
Institute
National Center for Research Resources (NCRR)
Type
Biotechnology Resource Grants (P41)
Project #
2P41RR000995-24
Application #
6118660
Study Section
Project Start
1999-05-15
Project End
2000-04-30
Budget Start
1998-10-01
Budget End
1999-09-30
Support Year
24
Fiscal Year
1999
Total Cost
Indirect Cost
Name
Massachusetts Institute of Technology
Department
Type
DUNS #
City
Cambridge
State
MA
Country
United States
Zip Code
02139
Marintchev, Assen; Edmonds, Katherine A; Marintcheva, Boriana et al. (2009) Topology and regulation of the human eIF4A/4G/4H helicase complex in translation initiation. Cell 136:447-60
Frueh, Dominique P; Arthanari, Haribabu; Koglin, Alexander et al. (2009) A double TROSY hNCAnH experiment for efficient assignment of large and challenging proteins. J Am Chem Soc 131:12880-1
Frueh, Dominique P; Leed, Alison; Arthanari, Haribabu et al. (2009) Time-shared HSQC-NOESY for accurate distance constraints measured at high-field in (15)N-(13)C-ILV methyl labeled proteins. J Biomol NMR 45:311-8
Lentz, Margaret R; Westmoreland, Susan V; Lee, Vallent et al. (2008) Metabolic markers of neuronal injury correlate with SIV CNS disease severity and inoculum in the macaque model of neuroAIDS. Magn Reson Med 59:475-84
Chen, Jingyang; Dupradeau, Francois-Yves; Case, David A et al. (2007) Nuclear magnetic resonance structural studies and molecular modeling of duplex DNA containing normal and 4'-oxidized abasic sites. Biochemistry 46:3096-107
Hyberts, Sven G; Heffron, Gregory J; Tarragona, Nestor G et al. (2007) Ultrahigh-resolution (1)H-(13)C HSQC spectra of metabolite mixtures using nonlinear sampling and forward maximum entropy reconstruction. J Am Chem Soc 129:5108-16
Lentz, Margaret R; Kim, John P; Westmoreland, Susan V et al. (2005) Quantitative neuropathologic correlates of changes in ratio of N-acetylaspartate to creatine in macaque brain. Radiology 235:461-8
Kim, John P; Lentz, Margaret R; Westmoreland, Susan V et al. (2005) Relationships between astrogliosis and 1H MR spectroscopic measures of brain choline/creatine and myo-inositol/creatine in a primate model. AJNR Am J Neuroradiol 26:752-9
Peled, S; Cory, D G; Raymond, S A et al. (1999) Water diffusion, T(2), and compartmentation in frog sciatic nerve. Magn Reson Med 42:911-8
Mo, H; Dai, Y; Pochapsky, S S et al. (1999) 1H, 13C and 15N NMR assignments for a carbon monoxide generating metalloenzyme from Klebsiella pneumoniae. J Biomol NMR 14:287-8

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