Geoffrey Bodenhausen

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In systems with dipolar relaxation in isotropic phase, it is possible to measure the extent of cross correlation of the fluctuations of two selected dipole-dipole interactions A-M and A-X by selectively exciting and spin-locking the transverse magnetization of spin A. If the system comprises only three spins A, M, and X, the conversion of in-phase magnetization IxA into doubly antiphase magnetization 4IxAIzMIzX during the spin-locking period occurs spontaneously through relaxation. The rate of this conversi

Although labile protons that are exchanging rapidly with those of the solvent cannot be observed directly, their exchange rate constants can be determined by indirect detection of scalar-coupled neighboring nuclei. We have used heteronuclear NMR spectrosco ...

A new method is presented for decoupling spins with S = 1 like D in anisotropic media while observing other spins such as residual protons in partly deuterated samples. The carrier frequency of a weak radiofrequency (RF) field is applied near the center of the doublet arising from the quadrupolar interaction of the S = 1 spins. The phase of the RF field is periodically reversed with intervals matching the reciprocal of the magnitude of the quadrupolar splitting. It is shown by theory and expt. that, even wh

In this article, a formal expression for the conformational entropy of a bond vector in a protein is derived using the networks of coupled rotators model for the description of internal dynamics. Analytical relationships between NMR order parameters and co ...

Side-chain carboxyl and carbonyl groups play a major role in protein interactions and enzyme catalysis. A series of C-13 relaxation experiments is introduced to study the dynamics of carboxyl and carbonyl groups in protein side chains on both fast (sub-ns) ...

Multiple quantum NMR allows straightforward identification of networks of scalar coupled spins. The information obtained is particularly useful for the identification of magnetic equivalence when multiplet splittings are not fully resolved. The interpretation of multiple quantum spectra is based on a set of simple selection rules which restrict coherence transfer between multiple quantum and single quantum transitions. [on SciFinder (R)]

We report measurements of spin-lattice relaxation of carbon-13 as a function of the magnetic field ('relaxometry') in view of optimizing dissolution-DNP. The sample is temporarily lifted into the stray field above a high-resolution magnet using a simple and inexpensive 'shuttle'. The signals of arbitrary molecules can be observed at high field with high-resolution and sensitivity. During the dissolution process and subsequent 'voyage' from the polarizer to the NMR magnet, relaxation is accelerated by parama

Theoretical and experimental investigations of the relaxation rates of multiple-quantum coherences during heteronuclear double resonance (HDR) pulse sequences are presented. Average Liouvillian theory yields analytical expressions to describe the effective ...

New exptl. methods are presented that allow one to measure cross-correlation between the fluctuations of dipolar interactions and chem. shift anisotropy (CSA) in scalar coupled systems with two and three spins I = 1/2 in isotropic soln. The methods involve selective excitation of the transverse magnetization IAx of a chosen spin A, followed by selective spin locking of this magnetization. If the spin locking radiofrequency (RF) field is exactly on-resonance for spin A while leaving the other spins M and X u

A train of short rotor-synchronized pulses in the manner of Delays Alternating with Nutations for Tailored Excitation (DANTE) applied to nitrogen-14 nuclei (I = 1) in samples spinning at the magic angle at high frequencies (typically nu(rot) = 62.5 kHz so ...

Hyperpolarization of substrates for magnetic resonance spectroscopy (MRS) and imaging (MRI) by dissolution dynamic nuclear polarization (D-DNP) usually involves saturating the ESR transitions of polarizing agents (PAs; e.g., persistent radicals embedded in ...

This study is concerned with the effects of applying selective pulses to systems with strong 2nd-order scalar couplings in isotropic phase, where different transitions (rs) are assocd. with different transition matrix elements F(rs)+. Two unusual features can be distinguished: the nutation angle (flip angle) depends on the matrix element of the irradiated transition (rs), and, in contrast to the behavior of an isolated spin-1/2 system, the norm of the three single-transition operators [Ix(rs), Iy(rs), Iz(rs

In deuterated molecules such as [1-C-13]pyruvate-d(3), the nuclear spin polarization of C-13 nuclei can be enhanced by combining Hartmann-Hahn cross-polarization (CP) at low temperatures (1.2 K) with dissolution dynamic nuclear polarization (D-DNP). The po ...

The advent of online publishing greatly facilitates the dissemination of scientific results. This revolution might have led to the untimely death of many traditional publishing companies, since today's scientists are perfectly capable of writing, formattin ...

A new expt. allows the identification of residues that feature slow conformational exchange in macromols. Rotations about dihedral angles that are slower than the global correlation time tc cause a modulation of the isotropic chem. shifts of the nuclei. If these fluctuations are correlated they induce a differential line broadening between three-spin single-quantum and triple-quantum coherences involving three nuclei such as the carbonyl C', the neighboring amide nitrogen N and the amide proton HN belonging

Understanding how proteins function at the atomic level relies in part on a detailed characterization of their dynamics. Ubiquitin, a small single-domain protein, displays rich dynamic properties over a wide range of time scales. In particular, several reg ...

Composite pulses of the type (tau(p))(x)(2 tau(p))(-x)(3 tau(p))(x) allow one to excite the central transition of nuclei with half-integer spin with enhanced efficiency compared to a simple (tau(sp)(p))(x) pulse. The method has been tested on solid samples ...

In crowded NMR spectra, it is shown how longitudinal relaxation rates (lab.-frame rates 1/T1) can be measured by selective inversion-recovery of a chosen site A followed by selective transfer of magnetization to another site X through a scalar coupling JAX, prior to observation of the signal. Relaxation rates in the presence of spin-locking (rotating frame rates 1/T1r) can be measured by first transferring transverse magnetization selectively from site X to A, followed by selective spin-locking of the magne

Line broadening, which can arise from inhomogeneities or homogeneous relaxation effects that lead to finite lifetimes of quantum states, is the Achilles' heel of many forms of spectroscopy. We show that line broadening may be considerably reduced by exploiting long lifetimes associated with superpositions of quantum states with different symmetry, termed long-lived coherences. In proton NMR of arbitrary molecules (including proteins) in isotropic solution, the slow oscillatory decays of long-lived coherence

Monitoring the isotropic chemical shifts to calibrate the sample temperature presupposes a perfect stability of the static magnetic field. It can be difficult to satisfy this requirement in solid-state NMR measurements. This paper describes a simple way to ...

Geoffrey Bodenhausen

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Measurement of dipolar cross correlation in scalar-coupled systems

Exchange Rate Constants of Invisible Protons in Proteins Determined by NMR Spectroscopy

NMR of residual protons in partly deuterated anisotropic materials with phase-alternated decoupling of deuterium spins

Predicting conformational entropy of bond vectors in proteins by networks of coupled rotators

Multiple-Timescale Dynamics of Side-Chain Carboxyl and Carbonyl Groups in Proteins by C-13 Nuclear Spin Relaxation

Analysis of networks of coupled spins by multiple quantum NMR

Relaxometry of insensitive nuclei: Optimizing dissolution dynamic nuclear polarization

Heteronuclear Double Resonance in NMR Spectroscopy: Relaxation of Multiple Quantum Coherences

Measurement of cross-correlation of fluctuations of dipolar couplings and anisotropic chemical shifts by selective spin locking

Broadband excitation and indirect detection of nitrogen-14 in rotating solids using Delays Alternating with Nutation (DANTE)

Hybrid polarizing solids for pure hyperpolarized liquids through dissolution dynamic nuclear polarization

Curious consequences of strong coupling in NMR experiments involving selective pulses

Hyperpolarization of Deuterated Metabolites via Remote Cross-Polarization and Dissolution Dynamic Nuclear Polarization

On toxic effects of scientific journals

Triple Quantum Decoherence under Multiple Refocusing: Slow Correlated Chemical Shift Modulations of C' and N Nuclei in Proteins

Time Scales of Slow Motions in Ubiquitin Explored by Heteronuclear Double Resonance

Composite pulses for efficient excitation of half-integer quadrupolar nuclei in NMR of static and spinning solid samples

Measurement of relaxation rates in crowded NMR spectra by selective coherence transfer

Long-Lived Coherences for Homogeneous Line Narrowing in Spectroscopy

Determination of sample temperature in unstable static fields by combining solid-state Br-79 and C-13 NMR