Friday, May 29, 2015

An ERC-funded 3.5-year PhD position on solid-state and solution NMRof protein complexes in the Lewandowski group at University of Warwick, Coventry, UK.

From the Ampere Magnetic Resonance List



An ERC-funded 3.5-year PhD position on solid-state and solution NMR of protein complexes is available in the Lewandowski group at University of Warwick, Coventry, UK.

PhD position is available in the group of Dr Józef Lewandowski in Chemistry Department at the University of Warwick, Coventry, UK with a start date in Oct 2015. Application deadline 30 June 2015.

Description

This PhD project involves applications of solution and solid-state NMR to study structure and dynamics of protein complexes. In particular, emphasis will be placed on working with complexes from polyketide synthases, which are multicomponent enzymatic assembly lines for a range of useful natural products, for example, antibiotics that are effective against certain multidrug resistant infections. The aim is to use the obtained biophysical insights to facilitate rational engineering of polyketide synthases for synthetic biology applications.

The project will involve overexpression of isotopically labeled proteins, characterization of biomolecular systems by solution and solid-state NMR as well as other biophysical techniques and to lesser extent NMR method development.

This PhD project is a part of larger project involving several interdisciplinary collaborations providing an excellent opportunity for exposure to a wide range of biophysical, molecular and synthetic biology methods.

Warwick Chemistry is one of the top UK Chemistry Departments (further details at : http://www2.warwick.ac.uk/fac/sci/chemistry/). The project will be conducted at the Warwick Laboratory for Magnetic Resonance (http://www2.warwick.ac.uk/fac/sci/physics/research/condensedmatt/nmr/), which is a world-class biological and material science magnetic resonance set up hosting 7 academic staff from Physics and Chemistry and housing a suite of 8 solid-state NMR spectrometers (from 100 to 850 MHz), 2 dynamic nuclear polarization (DNP) spectrometers (94 and 200/400 GHz) and advanced EPR instrumentation. A wide range of magic angle spinning probes is available at the laboratory including number of 1.3 mm probes (spinning frequencies up to 67 kHz) and 0.8 mm probe (spinning frequencies up to 100 kHz). Solution NMR facilities include 500, 600 and 700 MHz spectrometers (http://chemnmr.warwick.ac.uk/). The project will also benefit from access to a soon-to-arrive dedicated 700 MHz solid-state NMR spectrometer and a Chemical Biology Research Facility providing cutting edge infrastructure for organic synthesis, molecular biology, protein chemistry, microbiology, radiochemistry and biophysical/biochemical analysis.

More info on the Lewandowski group can be found at: http://www2.warwick.ac.uk/fac/sci/chemistry/research/lewandowski/lewandowskigroup
The start date is Oct 2015.

Funding

This studentship provides 3.5 years of full funding for UK/EU students. Current stipend rate is £14210 pa.

Requirements

Motivated applicants should have (or be about to receive) an honours degree (at least 2.1 in the UK system or equivalent) in chemistry, physics or biology. Excellent writing and communication skills in English are required.

How to apply?

Motivated candidates should send a CV and cover letter to Dr Józef Lewandowski at j.r.lewandowski@warwick.ac.uk

Application deadline is 30 June 2015.

====================================
This is the AMPERE MAGNETIC RESONANCE mailing list:

NMR web database:

Importance of polarization transfer in reaction products for interpreting and analyzing CIDNP at low magnetic fields


Pravdivtsev AN, Yurkovskaya AV, Ivanov KL, Vieth HM. Importance of polarization transfer in reaction products for interpreting and analyzing CIDNP at low magnetic fields. J Magn Reson. 2015;254(0):35-47.


The magnetic field dependence of Chemically Induced Dynamic Nuclear Polarization (CIDNP) was studied for the amino acids N-acetyl histidine, N-acetyl tryptophan and N-acetyl tyrosine. It is demonstrated that at low field CIDNP is strongly affected by polarization redistribution in the diamagnetic molecules. Such a polarization transfer is of coherent nature and is due to spin coherences formed together with non-equilibrium population of the spin states. These coherences clearly manifest themselves in an oscillatory time dependence of polarization. Polarization transfer effects are most pronounced at nuclear spin Level Anti-Crossings (LACs), which also result in sharp features in the CIDNP field dependence. Thus, polarization transfer is an important factor, which has to be taken into account in order to interpret low-field CIDNP data on both qualitative and quantitative level. Possible applications of polarization transfer phenomena are also discussed in the paper. In particular, the role of LACs in spin order transfer is highlighted: LACs provide a new tool for precise manipulation of spin hyperpolarization and NMR enhancement of selected target spins.

Wednesday, May 27, 2015

Ph.D. position at ICSN, Paris-Saclay

From the Ampere Magnetic Resonance List




A Ph.D. position is available at the ICSN laboratory in Paris-Saclay University to work on fast NMR methods for the analysis of complex mixtures and their coupling to hyperpolarisation

Title: Ultrafast NMR analysis of complex mixtures

Supervisors: Carine Van Heijenoort and Jean-Nicolas Dumez

Project: The analysis of complex mixtures if a major challenge for the chemist. Multidimensional NMR techniques can achieve a “spectral separation” of the components of a mixture, with no need for sample purification, but conventional multidimensional experiments are time-consuming and suffer from the low sensitivity of NMR spectroscopy. 

This project aims at developing NMR-based tools for the analysis of complex mixtures, that exploit ultrafast NMR for speed and hyperpolarisation for sensitivity. The successful candidate will work on three complementary topics:

  • the development of fast 2D NMR methods for the separation of “pure” spectra from a mixture
  • the coupling of fast 2D NMR and hyperpolarisation techniques, including parahydrogen-induced polarisation
  • the analysis of complex mixtures of small molecules
Lab: The Institute for Natural Product Research (ICSN) is one of the largest chemistry research institutes in France. The NMR group works on analytical and structural chemistry and biology and is equipped with 5 NMR spectrometers (2 * 600 MHz, 700 MHz, 800 MHz, 950 MHz) for high-resolution liquid-state NMR research. 

The project will involve a collaboration on hyperpolarisation with Gaspard Huber and Patrick Berthault of the LSDRM group at CEA Saclay, (also part of Paris-Saclay University) The ICSN is located in Gif-sur-Yvette, 25 km south-west of Paris. It benefits from a green, enjoyable environment and is within easy reach of Paris rich social and cultural life. 

Candidate: The candidate should have a background in chemistry (preferentially analytical or physical) or physics, and a strong interest in both fundamental and applied aspects of magnetic resonance. 

Interested candidates should send a CV and a cover letter to
and


References:
A. Le Guennec, P. Giraudeau, S. Caldarelli and J.-N. Dumez, Chem. Commun., 51, 354 (2015).

M. André, M. Piotto, S. Caldarelli and J.-N. Dumez, Analyst, in press.

====================================
This is the AMPERE MAGNETIC RESONANCE mailing list:

NMR web database:

Hyperpolarized Nanodiamond with Long Spin Relaxation Times


Rej E, Gaebel T, Boele T, Waddington D, Reilly D. Hyperpolarized Nanodiamond with Long Spin Relaxation Times. ARXIV. 2015.


The use of hyperpolarized agents in magnetic resonance (MR), such as 13C-labeled compounds, enables powerful new imaging and detection modalities that stem from a 10,000-fold boost in signal. A major challenge for the future of the hyperpolarizaton technique is the inherently short spin relaxation times, typically < 60 seconds for 13C liquid-state compounds, which limit the time that the signal remains boosted. Here, we demonstrate that 1.1% natural abundance 13C spins in synthetic nanodiamond (ND) can be hyperpolarized at cryogenic and room temperature without the use of toxic free- radicals, and, owing to their solid-state environment, exhibit relaxation times exceeding 1 hour. Combined with the already established applications of NDs in the life-sciences as inexpensive fluorescent markers and non-cytotoxic substrates for gene and drug delivery, these results extend the theranostic capabilities of nanoscale diamonds into the domain of hyperpolarized MR.

Friday, May 22, 2015

Simultaneous DNP enhancements of (1)H and (13)C nuclei: theory and experiments

Shimon D, Hovav Y, Kaminker I, Feintuch A, Goldfarb D, Vega S. Simultaneous DNP enhancements of (1)H and (13)C nuclei: theory and experiments. Phys Chem Chem Phys. 2015;17(17):11868-83.


DNP on heteronuclear spin systems often results in interesting phenomena such as the polarization enhancement of one nucleus during MW irradiation at the "forbidden" transition frequencies of another nucleus or the polarization transfer between the nuclei without MW irradiation. In this work we discuss the spin dynamics in a four-spin model system of the form {ea-eb-((1)H,(13)C)}, with the Larmor frequencies omegaa, omegab, omegaH and omegaC, by performing Liouville space simulations. This spin system exhibits the common (1)H solid effect (SE), (13)C cross effect (CE) and in addition high order CE-DNP enhancements. Here we show, in particular, the "proton shifted (13)C-CE" mechanism that results in (13)C polarization when the model system, at one of its (13)C-CE conditions, is excited by a MW field at the zero quantum or double quantum electron-proton transitions omegaMW = omegaa +/- omegaH and omegaMW = omegab +/- omegaH. Furthermore, we introduce the "heteronuclear" CE mechanism that becomes efficient when the system is at one of its combined CE conditions |omegaa - omegab| = |omegaH +/- omegaC|. At these conditions, simulations of the four-spin system show polarization transfer processes between the nuclei, during and without MW irradiation, resembling the polarization exchange effects often discussed in the literature. To link the "microscopic" four-spin simulations to the experimental results we use DNP lineshape simulations based on "macroscopic" rate equations describing the electron and nuclear polarization dynamics in large spin systems. This approach is applied based on electron-electron double resonance (ELDOR) measurements that show strong (1)H-SE features outside the EPR frequency range. Simulated ELDOR spectra combined with the indirect (13)C-CE (iCE) mechanism, result in additional "proton shifted (13)C-CE" features that are similar to the experimental ones. These features are also observed experimentally in (13)C-DNP spectra of a sample containing 15 mM of trityl in a glass forming solution of (13)C-glycerol/H2O and are analyzed by calculating the basic (13)C-SE and (13)C-iCE shapes using simulated ELDOR spectra that were fitted to the experimental ones.

Wednesday, May 20, 2015

A high saturation factor in Overhauser DNP with nitroxide derivatives: the role of (14)N nuclear spin relaxation


Enkin N, Liu G, Gimenez-Lopez Mdel C, Porfyrakis K, Tkach I, Bennati M. A high saturation factor in Overhauser DNP with nitroxide derivatives: the role of (14)N nuclear spin relaxation. Phys Chem Chem Phys. 2015;17(17):11144-9.


Overhauser DNP enhancements of toluene were measured at a magnetic field of 0.35 Tesla in a series of chemically functionalized nitroxide radicals. We observe that the enhancements increase systematically with polarizer size and rotational correlation time. Examination of the saturation factor of (14)N nitroxides by pulsed ELDOR spectroscopy led to a quantitative interpretation of the enhancements, for which the saturation factor increases up to almost unity due to enhanced nuclear ((14)N) relaxation in the nitroxide radical. The observation has a direct impact on the choice of optimum DNP polarizers in liquids.

Monday, May 18, 2015

Systematic T1 improvement for hyperpolarized (129)xenon


Repetto M, Babcock E, Blumler P, Heil W, Karpuk S, Tullney K. Systematic T1 improvement for hyperpolarized (129)xenon. J Magn Reson. 2015;252(0):163-9.


The spin-lattice relaxation time T1 of hyperpolarized (HP)-(129)Xe was improved at typical storage conditions (i.e. low and homogeneous magnetic fields). Very long wall relaxation times T1(wall) of about 18h were observed in uncoated, spherical GE180 glass cells of slashed circle=10cm which were free of rubidium and not permanently sealed but attached to a standard glass stopcock. An "aging" process of the wall relaxation was identified by repeating measurements on the same cell. This effect could be easily removed by repeating the initial cleaning procedure. In this way, a constant wall relaxation was ensured. The Xe nuclear spin-relaxation rate 1/T1(Xe-Xe) due to van der Waals molecules was investigated too, by admixing three different buffer gases (N2, SF6 and CO2). Especially CO2 exhibited an unexpected high efficiency (r) in shortening the lifetime of the Xe-Xe dimers and hence prolonging the total T1 relaxation even further. These measurements also yielded an improved accuracy for the van der Waals relaxation for pure Xe (with 85% (129)Xe) of T1(Xe-Xe)=(4.6+/-0.1)h. Repeating the measurements with HP (129)Xe in natural abundance in mixtures with SF6, a strong dependence of T1(Xe-Xe) and r on the isotopic enrichment was observed, uncovering a shorter T1(Xe-Xe) relaxation for the (129)Xe in natural composition as compared to the 85% isotopically enriched gas.

Friday, May 15, 2015

Thermosetting polymer for dynamic nuclear polarization: Solidification of an epoxy resin mixture including TEMPO


Noda, Y., et al., Thermosetting polymer for dynamic nuclear polarization: Solidification of an epoxy resin mixture including TEMPO. Nucl. Instrum. Methods Phys. Res., Sect. A, 2015. 776(0): p. 8-14.


We investigated the dynamic nuclear polarization (DNP) of typical thermosetting polymers (two-component type epoxy resins; Araldite® Standard or Araldite® Rapid) doped with a (2,2,6,6-tetramethylpiperidine-1-yl)oxy (TEMPO) radical. The doping process was developed by carefully considering the decomposition of TEMPO during the solidification of the epoxy resin. The TEMPO electron spin in each two-component paste decayed slowly, which was favorable for our study. Furthermore, despite the dissolved TEMPO, the mixture of the two-component paste successfully solidified. With the resulting TEMPO-doped epoxy-resin samples, DNP experiments at 1.2 K and 3.35 T indicated a magnitude of a proton-spin polarization up to 39%. This polarization is similar to that (35%) obtained for TEMPO-doped polystyrene (PS), which is often used as a standard sample for DNP. To combine this solidification of TEMPO-including mixture with a resin-casting technique enables a creation of polymeric target materials with a precise and complex structure.

Wednesday, May 13, 2015

Simultaneous hyperpolarized (13)C-pyruvate MRI and (18)F-FDG-PET in cancer (hyperPET): feasibility of a new imaging concept using a clinical PET/MRI scanner


Gutte, H., et al., Simultaneous hyperpolarized (13)C-pyruvate MRI and (18)F-FDG-PET in cancer (hyperPET): feasibility of a new imaging concept using a clinical PET/MRI scanner. American Journal of Nuclear Medicine and Molecular Imaging, 2015. 5(1): p. 38-45.


In this paper we demonstrate, for the first time, the feasibility of a new imaging concept - combined hyperpolarized (13)C-pyruvate magnetic resonance spectroscopic imaging (MRSI) and (18)F-FDG-PET imaging. This procedure was performed in a clinical PET/MRI scanner with a canine cancer patient. We have named this concept hyper PET. Intravenous injection of the hyperpolarized (13)C-pyruvate results in an increase of (13)C-lactate, (13)C-alanine and (13)C-CO(2) ((13)C-HCO(3)) resonance peaks relative to the tissue, disease and the metabolic state probed. Accordingly, with dynamic nuclear polarization (DNP) and use of (13)C-pyruvate it is now possible to directly study the Warburg Effect through the rate of conversion of (13)C-pyruvate to (13)C-lactate. In this study, we combined it with (18)F-FDG-PET that studies uptake of glucose in the cells. A canine cancer patient with a histology verified local recurrence of a liposarcoma on the right forepaw was imaged using a combined PET/MR clinical scanner. PET was performed as a single-bed, 10 min acquisition, 107 min post injection of 310 MBq (18)F-FDG. (13)C-chemical shift imaging (CSI) was performed just after FDG-PET and 30 s post injection of 23 mL hyperpolarized (13)C-pyruvate. Peak heights of (13)C-pyruvate and (13)C-lactate were quantified using a general linear model. Anatomic (1)H-MRI included axial and coronal T1 vibe, coronal T2-tse and axial T1-tse with fat saturation following gadolinium injection. In the tumor we found clearly increased (13)C-lactate production, which also corresponded to high (18)F-FDG uptake on PET. This is in agreement with the fact that glycolysis and production of lactate are increased in tumor cells compared to normal cells. Yet, most interestingly, also in the muscle of the forepaw of the dog high (18)F-FDG uptake was observed. This was due to activity in these muscles prior to anesthesia, which was not accompanied by a similarly high (13)C-lactate production. Accordingly, this clearly demonstrates how the Warburg Effect directly can be demonstrated by hyperpolarized (13)C-pyruvate MRSI. This was not possible with (18)F-FDG-PET imaging due to inability to discriminate between causes of increased glucose uptake. We propose that this new concept of simultaneous hyperpolarized (13)C-pyruvate MRSI and PET may be highly valuable for image-based non-invasive phenotyping of tumors. This methods may be useful for treatment planning and therapy monitoring.

Tuesday, May 12, 2015

PhD positions in NMR at EPFL

From the Ampere Magnetic Resonance List


PhD positions are available working with Professor Lyndon Emsley in the Laboratory for Magnetic Resonance at the EPFL in Lausanne, Switzerland,

The projects involve the development of new experimental methods to determine the structure of complex solid materials at different length scales, from atomic level structures to micro-meter level organisation and architecture. 

Approaches include dynamic nuclear polarization enhanced multi-dimensional correlation spectroscopy, high-resolution homonuclear dipolar decoupling, or the development of advanced computational methods using DFT to calculate NMR parameters or molecular modelling methods to calculate structures.

The goals are to determine structure-activity relations in pharmaceutical polymorphs, polymer composites, controlled release formulations, porous materials or catalytic surfaces.

The EPFL is one of the world’s leading universities, located on a beautiful campus on the shores of Lake Geneva. The Laboratory has extensive state-of-the-art equipment and infrastructure, including advanced solid-state DNP instrumentation. More information in can be found here: http://lrm.epfl.ch. The PhD positions are fully funded, and provide a high standard of living.

Motivated candidates with an undergraduate background in chemistry or physics should send their CVs to lyndon.emsley@epfl.ch

====================================
This is the AMPERE MAGNETIC RESONANCE mailing list:

NMR web database:

Monday, May 11, 2015

Molecular simulations for dynamic nuclear polarization in liquids: a case study of TEMPOL in acetone and DMSO


Kucuk, S.E., et al., Molecular simulations for dynamic nuclear polarization in liquids: a case study of TEMPOL in acetone and DMSO. Phys Chem Chem Phys, 2015. 17(9): p. 6618-28.


A computational strategy for calibrating, validating and analyzing molecular dynamics (MD) simulations to predict dynamic nuclear polarization (DNP) coupling factors and relaxivities of proton spins is presented. Simulations of the polarizing agent TEMPOL in liquid acetone and DMSO are conducted at low (infinite dilution) and high (1 M) concentrations of the free radical. Because DNP coupling factors and relaxivities are sensitive to the time scales of the molecular motions, the MD simulations are calibrated to reproduce the bulk translational diffusion coefficients of the pure solvents. The simulations are then validated by comparing with experimental dielectric relaxation spectra, which report on the rotational dynamics of the molecular electric dipole moments. The analysis consists of calculating spectral density functions (SDFs) of the magnetic dipole-dipole interaction between the electron spin of TEMPOL and nuclear spins of the solvent protons. Here, MD simulations are used in combination with an analytically tractable model of molecular motion. While the former provide detailed information at relatively short spin-spin distances, the latter includes contributions at large separations, all the way to infinity. The relaxivities calculated from the SDFs of acetone and DMSO are in excellent agreement with experiments at 9.2 T. For DMSO we calculate a coupling factor in agreement with experiment while for acetone we predict a value that is larger by almost 50%, suggesting a possibility for experimental improvement.

Wednesday, May 6, 2015

Microtesla SABRE enables 10% nitrogen-15 nuclear spin polarization


Theis, T., et al., Microtesla SABRE enables 10% nitrogen-15 nuclear spin polarization. J Am Chem Soc, 2015. 137(4): p. 1404-7.


Parahydrogen is demonstrated to efficiently transfer its nuclear spin hyperpolarization to nitrogen-15 in pyridine and nicotinamide (vitamin B(3) amide) by conducting "signal amplification by reversible exchange" (SABRE) at microtesla fields within a magnetic shield. Following transfer of the sample from the magnetic shield chamber to a conventional NMR spectrometer, the (15)N NMR signals for these molecules are enhanced by approximately 30,000- and approximately 20,000-fold at 9.4 T, corresponding to approximately 10% and approximately 7% nuclear spin polarization, respectively. This method, dubbed "SABRE in shield enables alignment transfer to heteronuclei" or "SABRE-SHEATH", promises to be a simple, cost-effective way to hyperpolarize heteronuclei. It may be particularly useful for in vivo applications because of longer hyperpolarization lifetimes, lack of background signal, and facile chemical-shift discrimination of different species.

Parahydrogen-Induced Polarization by Pairwise Replacement Catalysis on Pt and Ir Nanoparticles


Zhou, R., et al., Parahydrogen-Induced Polarization by Pairwise Replacement Catalysis on Pt and Ir Nanoparticles. J. Am. Chem. Soc., 2015. 137(5): p. 1938-1946.


Pairwise and random addition processes are ordinarily indistinguishable in hydrogenation reactions. The distinction becomes important only when the fate of spin correlation matters, such as in parahydrogen-induced polarization (PHIP). Supported metal catalysts were not expected to yield PHIP signals given the rapid diffusion of H atoms on the catalyst surface and in view of the sequential stepwise nature of the H atom addition in the Horiuti?Polanyi mechanism. Thus, it seems surprising that supported metal hydrogenation catalysts can yield detectable PHIP NMR signals. Even more remarkably, supported Pt and Ir nanoparticles are shown herein to catalyze pairwise replacement on propene and 3,3,3-trifluoropropene. By simply flowing a mixture of parahydrogen and alkene over the catalyst, the scalar symmetrization order of the former is incorporated into the latter without a change in molecular structure, producing intense PHIP NMR signals on the alkene. An important indicator of the mechanism of the pairwise replacement is its stereoselectivity, which is revealed with the aid of density matrix spectral simulations. PHIP by pairwise replacement has the potential to significantly diversify the substrates that can be hyperpolarized by PHIP for biomedical utilization.

PhD fellowship at the MR-Centre, Aarhus University

From the Ampere Magnetic Resonance List



OPEN CALLS

PhD fellowship at the MR-Centre, Aarhus University

A position as a PhD fellow exploring the state-of-the-art MR-hyperpolarization for investigation of metabolic changes in life style related diseases is now open. The successful applicant is expected to carry out scientific research towards a PhD degree. Application deadline is May 26th, 2015.

PhD in DNP MRI, Aarhus University, Denmark

Applications are invited for a PhD position to join the newly established hyperpolarization research group at Aarhus University (AU) with the purpose of refining the hyperpolarization technology further for study programs on metabolic flux associated with dietary patterns following acute and long-term effects of different protein supplements.

The successful applicant will work on a 3-year research project, exploring the technical, chemical and physical methods of hyperpolarization for in vivo applications. The PhD project includes development of new robust acquisition and reconstruction protocols for metabolic imaging in swine and rodents, utilizing simultaneous polarization and injection of multiple bio-probes.

Eligible candidates should hold a Master or similar degree in a relevant discipline, including (but not limited to) physics, engineering, chemistry, nanotechnology and mathematics. The position is to be filled as soon as possible and is open for up to 3 years.

The application is expected to carry out scientific research towards a PhD degree in collaboration with Assistant Prof. Christoffer Laustsen and Prof. Hans Stødkilde-Jørgensen as their academic supervisors, incorporating the contents in the bullets below.

· Bolus tracking method development for hyperpolarised MR
· Development and validation of in vivo co-polarization procedures of multiple bio-tracers.
· Interlace proton and carbon imaging acquisition and reconstruction.

Note that the selected candidate will subsequently have to apply for and get approved for enrolment at the AU Graduate School of Health (http://talent.au.dk/phd/health/), in a separate procedure before starting.

The MR-Centre is a core facility at the Department of Clinical Medicine, AU and provides cutting-edge basic and clinical translational research based on top MR technology, http://www.mr.au.dk. The Dept. Clinical Medicine has more than 1.140 research employees and more than 450 PhD’s. AU provides an inspiring international research environment and is consistently listed among the world’s best 100 universities. Aarhus is a dynamic university city located in continental Denmark and surrounded by nature; it offers very high living standards, rich cultural and intellectual life, etc.
[if !supportLineBreakNewLine]
[endif]

Additional information regarding this position can be obtained by contacting Prof. Hans Stødkilde- Jørgensen, hsj@clin.au.dk.

Applications, which should contain the applicant's CV, motivation letter, short (max 2 pages) research proposal and 2 academic references (or at least names and addresses of 2 referees), should reach Prof. Hans Stødkilde-Jørgensen, by May 26th, 2015. Note that only short-listed candidates will be contacted.


Best regards,
Chris


Christoffer Laustsen
MSc, PhD, Assistant Professor
MR-Research Centre, Aarhus University Hospital
Palle Juul-Jensens Boulevard 99
8200 Aarhus N
Denmark 

Tlf: +45 7845 6139
Mobile: +45 2443 9141

====================================
This is the AMPERE MAGNETIC RESONANCE mailing list:

NMR web database:

Monday, May 4, 2015

9th Field-Cycling NMR conference, Aberdeen, 27-30 July 2015

From the Ampere Magnetic Resonance List

The 9th Conference on Fast Field-Cycling NMR Relaxometry will be held at the University of Aberdeen, Scotland, from Monday 27th to Thursday 30th July, 2015.

This is the biennial Field-Cycling NMR conference, previously held in Berlin (1998) and then every two years in Torino until 2013. So it is the first move for the conference since 2001!

The conference covers all aspects of Fast Field-Cycling magnetic resonance, including theory, hardware, techniques, applications, relaxometry, imaging, as well as ultra-low field methods. Full details of the conference can be found at http://www.abdn.ac.uk/events/ffc-2015/

The deadline for receipt of abstracts is 8th May – just one week away! Please be sure to submit your abstract(s) on time, following the instructions on the conference web site.

Registration and accommodation booking and abstract submission are also open, on the web site.

Key dates:
Abstract submission deadline: 8th May
Registration deadline: 12th June
Accommodation deadline: 30th June

Low-price on-site accommodation in en-suite rooms is available, via the conference web site. Participants are advised to book accommodation early in order to be sure of securing a room.

Please note that, due to the prevalence of the local oil industry, hotel rooms in Aberdeen are scarce, and they are much more expensive than the on-site rooms.

The conference will be held in the state-of-the-art King’s Conference Centre, at the historic heart of the University of Aberdeen’s main campus. It will be hosted by the FFC-MRI research group.

I hope to see you in Aberdeen in July!
David Lurie (d.lurie@abdn.ac.uk)
Chair of Organising Committee

The University of Aberdeen is a charity registered in Scotland, No SC013683.

Tha Oilthigh Obar Dheathain na charthannas clàraichte ann an Alba, Àir. SC013683.

====================================
This is the AMPERE MAGNETIC RESONANCE mailing list:
http://www.drorlist.com/nmrlist.html

NMR web database:
http://www.drorlist.com/nmr.html

Cellular solid-state NMR investigation of a membrane protein using dynamic nuclear polarization


Yamamoto, K., et al., Cellular solid-state NMR investigation of a membrane protein using dynamic nuclear polarization. Biochimica et Biophysica Acta (BBA) - Biomembranes, 2015. 1848(1, Part B): p. 342-349.


While an increasing number of structural biology studies successfully demonstrate the power of high-resolution structures and dynamics of membrane proteins in fully understanding their function, there is considerable interest in developing NMR approaches to obtain such information in a cellular setting. As long as the proteins inside the living cell tumble rapidly in the NMR timescale, recently developed in-cell solution NMR approaches can provide 3D structural information. However, there are numerous challenges to study membrane proteins inside a cell. Research in our laboratory is focused on developing a combination of solid-state NMR and biological approaches to overcome these challenges in order to obtain high-resolution structural insights into electron transfer processes mediated by membrane-bound proteins like mammalian cytochrome-b5, cytochrome-P450 and cytochrome-P450-reductase. In this study, we demonstrate the feasibility of using dynamic nuclear polarization (DNP) magic angle spinning (MAS) NMR spectroscopy for in-cell studies on a membrane-anchored protein. Our experimental results obtained from 13C-labeled membrane-anchored cytochrome-b5 in native Escherichia coli cells show a ~ 16-fold DNP signal enhancement. Further, results obtained from a 2D 13C/13C chemical shift correlation MAS experiment demonstrate the feasibility of suppressing the background signals from other cellular contents for high-resolution structural studies on membrane proteins. We believe that this study would pave new avenues for high-resolution structural studies on a variety of membrane-associated proteins and their complexes in the cellular context to fully understand their functional roles in physiological processes. This article is part of a Special Issue entitled: NMR Spectroscopy for Atomistic Views of Biomembranes and Cell Surfaces. Guest Editors: Lynette Cegelski and David P. Weliky.

Friday, May 1, 2015

Is solid-state NMR enhanced by dynamic nuclear polarization?


Lee, D., S. Hediger, and G. De Paepe, Is solid-state NMR enhanced by dynamic nuclear polarization? Solid State Nucl Magn Reson, 2015. 66-67C(0): p. 6-20.


The recent trend of high-field (~5-20T), low-temperature (~100K) ssNMR combined with dynamic nuclear polarization (DNP) under magic angle spinning (MAS) conditions is analyzed. A brief overview of the current theory of hyperpolarization for so-called MAS-DNP experiments is given, along with various reasons why the DNP-enhancement, the ratio of the NMR signal intensities obtained in the presence and absence of microwave irradiation suitable for hyperpolarization, should not be used alone to gauge the value of performing MAS-DNP experiments relative to conventional ssNMR. This is demonstrated through a dissection of the current conditions required for MAS-DNP with particular attention to resulting absolute sensitivities and spectral resolution. Consequently, sample preparation methods specifically avoiding the surplus of glass-forming solvents so as to improve the absolute sensitivity and resolution are discussed, as are samples that are intrinsically pertinent for MAS-DNP studies (high surface area, amorphous, and porous). Owing to their pertinence, examples of recent applications on these types of samples where chemically-relevant information has been obtained that would have been impossible without the sensitivity increases bestowed by MAS-DNP are also detailed. Additionally, a promising further implementation for MAS-DNP is exampled, whereby the sensitivity improvements shown for (correlation) spectroscopy of nuclei at low natural isotopic abundance, facilitate internuclear distance measurements, especially for long distances (absence of dipolar truncation). Finally, we give some speculative perspectives for MAS-DNP.