Geoffrey Bodenhausen

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The observation of nuclear Overhauser effects (NOEs) between bound water and biol. macromols. such as proteins and nucleic acids can be improved by inverting the water resonance selectively while compensating for radiation damping effects. The efficiency of inversion, the offset profiles, and the appearance of 2D NOE-NOESY spectra can be improved in comparison with earlier methods. [on SciFinder (R)]

One-dimensional NOE expts. applicable to labeled macromols. are presented which allow the manipulation of specific spin diffusion pathways and thus unambiguously identify clandestine spins through which the direct NOE is mediated. A treatment of spin diffusion using av. Liouvillian theory is shown to describe adequately these phenomena. Expts. are carried out on an 15N-labeled sample of human ubiquitin. (c) 1999 Academic Press. [on SciFinder (R)]

Overhauser effects and hence internuclear distances can be measured accurately with selective expts. designed to suppress spin diffusion. It is essential to consider effects of both transverse and longitudinal relaxation during selective radiofrequency pulses. Fitting procedures allow one to refine selected cross-relaxation rate consts., and hence det. internuclear distances with improved accuracy. For the sake of illustration, selected cross-relaxation rates are detd. that correspond to short- and long-ran

We demonstrate fast characterization of the distribution of surface bonding modes and interactions in a series of functionalized materials via surface-enhanced nuclear magnetic resonance spectroscopy using dynamic nuclear polarization (DNP). Surface-enhanced silicon-29 DNP NMR spectra were obtained by using incipient wetness impregnation of the sample with a solution containing a polarizing radical (TOTAPOL). We identify and compare the bonding topology of functional groups in materials obtained via a sol g

By simultaneously irradiating the resonances of 2 selected nuclei in a macromol. with selective radio-frequency fields, one can measure the cross-relaxation rate (Overhauser effect) between 2 sites without perturbations due to spin-diffusion effects involving other spins in the mol. Applications are shown to Ha to Tyr-23 and Ha of Cys-30 in basic pancreatic trypsin inhibitor (BPTI). [on SciFinder (R)]

A method was developed for measuring the rise and fall curves corresponding to selected peaks in NOESY spectrum. When applied to a std. two-dimensional NOESY spectrum, this technique gives result the resoln. of which is similar to that of the three-dimensional method. The proposed pulse sequence was demonstrated on spectra of some oligonucleotides. [on SciFinder (R)]

A double quantum filter is inserted into a 2-dimensional correlated (COSY) 1H NMR expt. to obtain phase-sensitive spectra in which both cross-peak and diagonal-peak multiplets have antiphase fine structure, and in which the cross peaks and the major contribution to the diagonal peaks have absorption lineshapes in both dimensions. The elimination of the dispersive character of the diagonal peaks in phase-sensitive, double quantum-filtered COSY spectra allows identification of cross peaks lying immediately ad

An expt. is described which uses essentially the same pulse sequence as 2-dimensional (2D) exchange spectroscopy (NOESY), but where the flip angles of the 2 pulses that precede and follow the mixing period tm are small (b .simeq.20 Deg). Use of a NOESY-like sequence is proposed, where tm is chosen to be too short to allow exchange phenomena to play a role, and serves merely to eliminate coherence-transfer pathways through single-, multiple-, and zero-quantum coherences, while retaining only transfer process

The effect of multiexponential transverse relaxation of degenerate transitions on coherence transfer phenomena in high-resoln. NMR is discussed. Dipolar relaxation of X3 and AX3 systems is considered, and the implications for multiple-quantum-filtered 2-dimensional correlation spectra of large mols. are analyzed. An expansion of the d. operator in terms of products of irreducible tensor operators is used for tracing the pathways of coherence transfer. [on SciFinder (R)]

The exptl. verification of offset profiles and calibration of selective pulses in NMR is usually carried out with doped water samples but not under conditions typical of macromols. with short T2, long T1, and possibly homo- and heteronuclear couplings. A new method for selective excitation in isotopically labeled macromols. is shown to be particularly suited to this purpose. This is illustrated for a backbone amide resonance in a sample of 15N-labeled human ubiquitin. (c) 1999 Academic Press. [on SciFinder

In the long bygone days of continuous-wave nuclear magnetic resonance (NMR) spectroscopy, a selected transition within a multiplet of a high-resolution spectrum could be irradiated by a highly selective continuous-wave (CW) radio-frequency (rf) field with ...

The authors describe how the value of a nuclear spin coupling const. JAX can be detd. very accurately by comparing 2 complementary 2-dimensional multiplets obtained with selective correlation NMR spectroscopy (soft-COSY) and with pure in-phase correlation spectroscopy. The convolution method of J. J. Titman and J. Keeler (1990) was adapted to compare soft-COSY and PICSY multiplets. Illustrative results on the L-proline residue in cyclo-(L-Pro1-L-Pro2-D-Pro3) are presented. [on SciFinder (R)]

Exptl. evidence is given to support the prior claims of the authors that multiplets in z-filtered double-quantum spectra have better peak shapes than those in conventional double-quantum spectra. The expts. were done on trans-2-phenylcyclopropanecarboxylic acid. [on SciFinder (R)]

It is demonstrated, on the grounds of simulations, how 270 degrees Gaussian pulses can be used for slice selection in nuclear magnetic resonance imaging experiments. It is shown that the usual gradient reversal procedure can be omitted if the selective 90 degrees pulse normally used is replaced by a self-refocusing 270 degrees pulse with a Gaussian time-domain amplitude profile, and some of the properties which are specific to this type of pulse are explored. [on SciFinder (R)]

Passive spin filters are combined with pure in-phase correlation spectroscopy (PICSY) to obtain SIS-(p,q)-PICSY expts., where p and q are the nos. of passive spins that are simultaneously or sequentially inverted during the evolution period and that are coupled to both source and target spins, resp. Conventional PICSY and SIS-(0,1)-PICSY spectra of cyclo-(L-proline1-L-proline2-D-proline3) are compared. [on SciFinder (R)]

Long-lived coherences (LLCs) in homonuclear pairs of chemically inequivalent spins can be excited and sustained during protracted radio frequency irradiation periods that alternate with brief windows for signal observation. Fourier transformation of the su ...

The relaxation of long-lived states (LLS) corresponds to the slow return to statistical thermal equilibrium between symmetric and antisymmetric proton spin states. This process is remarkably sensitive to the presence of external spins and can be used to ob ...

Heteronuclear 2-dimensional NMR was used to correlate the 1H and 31P chem. shifts of cellular phosphates. Exptl. spectra agree with theor. predictions based on a novel approach using subspectral anal. The spectra are sensitive to the homonuclear scalar couplings between the protons as well as the heteronuclear 1H-31P coupling. Thus, the 2-dimensional spectra provide information about the conformation of cellular phosphates. Since 1H signals are only obsd. from those protons located in the vicinity of the ph

It is shown how amplitude-modulated radio-frequency pulses optimized for selective inversion of magnetization can be applied to static powder samples with inhomogeneously broadened spectra. Selective one-dimensional methods can in principle provide information similar to two-dimensional exchange spectroscopy, and they are often more efficient for detg. the rates of dynamic processes. However, in systems where transverse magnetization is subject to significant homogeneous decay during the rf pulses, selectiv

Geoffrey Bodenhausen

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Radiation damping compensation of selective pulses in water-protein exchange spectroscopy

Identification of Spin Diffusion Pathways in Isotopically Labeled Biomolecules

Quantitative determination of cross-relaxation rates in NMR using selective pulses to inhibit spin diffusion

Fast Characterization of Functionalized Silica Materials by Silicon-29 Surface-Enhanced NMR Spectroscopy Using Dynamic Nuclear Polarization

Measurement of Overhauser effects in magnetic resonance of proteins by synchronous nutation

Selective Measurement of the Time‐Dependence of Transient Overhauser Effects in Magnetic Resonance: Applications to Oligonucleotides

Improved spectral resolution in COSY proton NMR spectra of proteins via double quantum filtering

Two-dimensional correlation of directly and remotely connected transitions by z-filtered COSY

Relaxation-induced violations of coherence transfer selection rules in nuclear magnetic resonance

Offset Profiles of Selective Pulses in Isotopically Labeled Macromolecules

How to Tickle Spins with a Fourier Transform NMR Spectrometer

Accurate determination of scalar couplings by convolution of complementary two-dimensional multiplets

Multiplet effects in double-quantum spectra

Self-refocusing 270 degrees Gaussian pulses for slice selection without gradient reversal in magnetic resonance imaging

Generation of complementary multiplets for automated analysis of selective correlation spectra

Ultra High-Resolution NMR: Sustained Induction Decays of Long-Lived Coherences

Long-Lived States to Monitor Protein Unfolding by Proton NMR

Heteronuclear two-dimensional NMR as a conformational probe of cellular phosphates

Selective inversion in inhomogeneously broadened powder spectra

Fractional Spin-Labeling of Polymers for Enhancing NMR Sensitivity by Solvent-Free Dynamic Nuclear Polarization