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Spin Noise Detection of Nuclear Hyperpolarization at 1.2 K

 

ChemPhysChem Volume 16, Issue 18, December 2015, Pages 3859–3864

 

We report proton spin noise spectra of a hyperpolarized solid sample of commonly used “DNP (dynamic nuclear polarization) juice” containing TEMPOL (4-hydroxy-2,2,6,6-tetramethylpiperidine N-oxide) and irradiated by a microwave field at a temperature of 1.2 K in a magnetic field of 6.7 T. The line shapes of the spin noise power spectra are sensitive to the variation of the microwave irradiation frequency and change from dip to bump, when the electron Larmor frequency is crossed, which is shown to be in good accordance with theory by simulations. Small but significant deviations from these predictions are observed, which can be related to spin noise and radiation damping phenomena that have been reported in thermally polarized systems. The non-linear dependence of the spin noise integral on nuclear polarization provides a means to monitor hyperpolarization semi-quantitatively without any perturbation of the spin system by radio frequency irradiation.

Proteomic comparison of the EWS-FLI1 expressing cells EF with NIH-3T3 and actin remodeling effect of (R/W)9 cell-penetrating peptide

 

EuPA Open Proteomics 2016;10:1-8

 

EWS-FLI1 expression in NIH-3T3 fibroblasts has a profound impact on the phenotype, resulting in the cytoskeleton and adhesive capacity disorganization (EF cells). Besides this, (R/W)9, a cell-penetrating peptide (CPP), has an intrinsic actin remodeling activity in EF cells. To evaluate the impact of the oncogenic protein EWS-FLI1 on proteins expression levels, a quantitative comparison of tumoral EF and non-tumoral 3T3 proteomes was performed. Then to see if we could link the EWS-FLI1 oncogenic transformation to the phenotype reversion induced by (R/W)9, (R/W)9 influence on EF cells proteome was assessed. To our knowledge no such “CPPomic” study has been performed before.

 

 

Entasis through Hook-and-Loop Fastening in a Glycoligand with Cumulative Weak Forces Stabilizing Cu(I)

J. Am. Chem. Soc.2015

The idea of a possible control of metal ion properties by constraining the coordination sphere geometry was introduced by Vallee and Williams with the concept of entasis, which is frequently postulated to be at stake in metallobiomolecules. However, the interactions controlling the geometry at metal centers remain often elusive. In this study, the coordination properties toward copper ions - Cu(II) or Cu(I) - of a geometrically constrained glycoligand centered on a sugar scaff old were compared with those of an analogous ligand built on an unconstrained alkyl chain. The sugar-centered ligand was shown to be more preorganized for Cu(II)  coordination than its open-chain analogue, with an unusual additional stabilization of the Cu(I)  redox state.

An easy-to-detect nona-arginine peptide for epidermal targeting

 

Chem. Commun., 2015, 51, 2687-2689

 

A correlative approach combining synchrotron radiation based IR microscopy and fluorescence microscopy enabled the successful detection and quantification of a nona-arginine peptide labelled with a Single Core Multimodal Probe for Imaging (SCoMPI) in skin biopsies. The topical penetration of the conjugate appeared to be time dependent and occurred most probably via the extracellular matrix.

 

 

Nanosecond motions in proteins revealed by high-resolution relaxometry

A proper description of biological processes at the atomic level require a full characterization of both the structure and the dynamics of biomolecules. Nuclear magnetic resonance (NMR) is a method of choice to access both to the structure and the dynamics of proteins and nucleic acids. One of most powerful NMR probes of biomolecular dynamics is nuclear spin relaxation. Here, we show that nanosecond time scale motions can be revealed with an emerging technique: high-resolution relaxometry.