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Storing slow processes in spin memory: long-lived states

Applicant Vasos Paul Romeo
Number 121928
Funding scheme Ambizione
Research institution Laboratoire de résonance magnétique biomoléculaire EPFL - SB - ISIC - LRMB
Institution of higher education EPF Lausanne - EPFL
Main discipline Physical Chemistry
Start/End 01.11.2008 - 31.10.2011
Approved amount 321'750.00
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All Disciplines (3)

Discipline
Physical Chemistry
Biophysics
Biochemistry

Keywords (5)

slow diffusion; long-lived states; hyperpolarisation; nuclear magnetic resonance (NMR); slow exchange

Lay Summary (English)

Lead
Lay summary
The duration of nuclear magnetic resonance (NMR) experiments is limited to the time interval after which the spins lose memory of their initial state, via relaxation mechanisms. Under particular conditions, a group of spins may be found in a state that is immune to relaxation processes, and therefore has a long lifetime; this is a long-lived state (LLS). This observation opens the way to NMR studies of slow transport and exchange phenomena, such as blood flow or certain dynamic events occurring in proteins and nucleic acids.
Methods will be developed to use long-lived states in biomolecules, by extending these states to specific groups of spins in aminoacids. This will permit to characterise biomolecular conformations that occur in vivo in slow exchange with the native form, such as, for instance, equilibria between folded and unfolded states.
The sensitivity of nuclear resonance experiments is intrinsically low, but it can be enhanced by several orders of magnitude (up to 10’000 times) through hyperpolarisation, that is, transfer of magnetisation from electron spins. We plan to use long-lived states as a reservoir and transport vector for hyperpolarised nuclear magnetisation, so the enhanced signals may be observed at the desired time and location, for instance in magnetic resonance imaging (MRI). To this effect, long-lived states will be generated in endogenous molecules that may be followed in vivo.
Direct link to Lay Summary Last update: 21.02.2013

Responsible applicant and co-applicants

Employees

Publications

Publication
Long-Lived States to Monitor Protein Unfolding by Proton NMR
Bornet A, Ahuja P, Sarkar R, Fernandes L, Hadji S, Lee SY, Haririnia A, Fushman D, Bodenhausen G, Vasos PR (2011), Long-Lived States to Monitor Protein Unfolding by Proton NMR, in CHEMPHYSCHEM, 12(15), 2729-2734.
Extending Timescales and Narrowing Linewidths in NMR
Segawa TF, Bornet A, Salvi N, Mieville P, Vitzthum V, Carnevale D, Jannin S, Caporini MA, Ulzega S, Vasos PR, Rey M, Bodenhausen G (2011), Extending Timescales and Narrowing Linewidths in NMR, in CHIMIA, 65(9), 652-655.
Long-lived coherences for line-narrowing in high-field NMR
Sarkar R, Ahuja P, Vasos PR, Bornet A, Wagnieres O, Bodenhausen G (2011), Long-lived coherences for line-narrowing in high-field NMR, in PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY, 59(1), 83-90.
Proton hyperpolarisation preserved in long-lived states
Ahuja P, Sarkar R, Jannin S, Vasos PR, Bodenhausen G (2010), Proton hyperpolarisation preserved in long-lived states, in CHEMICAL COMMUNICATIONS, 46(43), 8192-8194.
Scavenging Free Radicals To Preserve Enhancement and Extend Relaxation Times in NMR using Dynamic Nuclear Polarization
Mieville P, Ahuja P, Sarkar R, Jannin S, Vasos PR, Gerber-Lemaire S, Mishkovsky M, Comment A, Gruetter R, Ouari O, Tordo P, Bodenhausen G (2010), Scavenging Free Radicals To Preserve Enhancement and Extend Relaxation Times in NMR using Dynamic Nuclear Polarization, in ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 49(35), 6182-6185.
Scavenging Free Radicals To Preserve Enhancement and Extend Relaxation Times in NMR using Dynamic Nuclear Polarization (vol 49, pg 6182, 2010)
Mieville P, Ahuja P, Sarkar R, Jannin S, Vasos PR, Gerber-Lemaire S, Mishkovsky M, Comment A, Gruetter R, Ouari O, Tordo P, Bodenhausen G (2010), Scavenging Free Radicals To Preserve Enhancement and Extend Relaxation Times in NMR using Dynamic Nuclear Polarization (vol 49, pg 6182, 2010), in ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 49(43), 7834-7834.
Hyperpolarizing Gases via Dynamic Nuclear Polarization and Sublimation
Comment A, Jannin S, Hyacinthe JN, Mieville P, Sarkar R, Ahuja P, Vasos PR, Montet X, Lazeyras F, Vallee JP, Hautle P, Konter JA, van den Brandt B, Ansermet JP, Gruetter R, Bodenhausen G (2010), Hyperpolarizing Gases via Dynamic Nuclear Polarization and Sublimation, in PHYSICAL REVIEW LETTERS, 105(1), 100-105.
Long-Lived Coherences for Homogeneous Line Narrowing in Spectroscopy
Sarkar R, Ahuja P, Vasos PR, Bodenhausen G (2010), Long-Lived Coherences for Homogeneous Line Narrowing in Spectroscopy, in PHYSICAL REVIEW LETTERS, 104(5), 224-238.
Proton NMR of N-15-Choline Metabolites Enhanced by Dynamic Nuclear Polarization
Sarkar R, Comment A, Vasos PR, Jannin S, Gruetter R, Bodenhausen G, Hall H, Kirik D, Denisov VP (2009), Proton NMR of N-15-Choline Metabolites Enhanced by Dynamic Nuclear Polarization, in JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 131(44), 16014-16014.
Long-lived states to sustain hyperpolarized magnetization
Vasos PR, Comment A, Sarkar R, Ahuja P, Jannin S, Ansermet JP, Konter JA, Hautle P, van den Brandt B, Bodenhausen G (2009), Long-lived states to sustain hyperpolarized magnetization, in PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 106(44), 18469-18473.
Long-lived States in Multiple-Spin Systems
Ahuja P, Sarkar R, Vasos PR, Bodenhausen G (2009), Long-lived States in Multiple-Spin Systems, in CHEMPHYSCHEM, 10(13), 2217-2220.
Diffusion Coefficients of Biomolecules Using Long-Lived Spin States
Ahuja P, Sarkar R, Vasos PR, Bodenhausen G (2009), Diffusion Coefficients of Biomolecules Using Long-Lived Spin States, in JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 131(22), 7498-7498.

Associated projects

Number Title Start Funding scheme
124694 Methods for enhancing sensitivity and magnetisation lifetimes in liquid- and solid-state NMR 01.04.2009 Project funding (Div. I-III)

Abstract

Long-lived states (LLS) are nuclear spin configurations delocalised on two or more coupled spins that have unusually long relaxation times, thus allowing to follow very slow processes by NMR. The favourable relaxation properties of LLS are due to the fact that their decay rates are not affected by dipolar interactions between the spins involved. We intend to establish long-lived states as a method that extends the application range of NMR in macromolecules to slowly exchanging or slowly diffusing systems. Applications will be developed that will allow to use LLS in protein samples, study ligand-protein interactions, differentiate between slow diffusion coefficients of co-mixed substances in solution, and extend the use of LLS to nuclei other than 1H (e.g. 13C).Our project is to combine the advantages of long-lived states with the use of enhanced magnetization obtained via Dynamic Nuclear Polarisation (DNP). The new experiment, termed DNP-LLS, will also find applications for Magnetic Resonance Imaging.
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