Today we recognize the central role that intrinsically disordered proteins (IDPs) play in cellular processes. This was not always the case. To understand why the IDP concept had not surfaced previously, we need to take ourselves back to the scientific mindset before 1990. The human genome project was not on anybody’s radar – very few if any genes had been sequenced. Cloning and expression of...
Intrinsically disordered proteins (IDPs) are highly abundant in the human proteome and are strongly associated with numerous devastating diseases, including cancers, age-related neurodegenerative disorders, diabetes, cardiovascular and infectious diseases. IDPs mediate critical regulatory functions in the cell, including transcription, translation, the cell cycle, and numerous signal...
Observing proteins structural changes at during function in-side the cell is a challenge yet to be met. In this context we have been developing in-cell 95 GHz DEER ( double- electron electron resonance) distance measurement using Gd(III) spin labels. The developments that enabled in cell DEER on proteins, including instrumental aspects, Gd(III) spectroscopic properties, the chemistry of the...
Those of us engaged in active experimental research careers rarely have the opportunity to step back from the lab bench or the computer to reflect on our own scientific practice. Long before descriptive terms such as “multidisciplinary” or “integrative” were fashionable, biological NMR (BioNMR), from its very beginnings, was multidisciplinary in and by itself. Integration of complementary data...
Membrane proteins are important players in signal transduction and the exchange of metabolites in cells. Thus, this protein class is the target of around 60% of currently marketed drugs, emphasizing their essential biological role. Besides production issues, a major bottleneck encountered in the structural characterization of membrane proteins is identifying a suitable membrane mimetic that...
Long-lived states are particular configurations of nuclear spins which are well-protected against relaxation mechanisms. These configurations appear as particular terms in the spin density operator associated with unusually slow decay rate constants. A seminal example arises in systems of homonuclear spin-1/2 pairs in solution. Singlet order, meaning a population imbalance between the singlet...
Dynamic nuclear polarization (DNP) is now established as a powerful technique for improving the sensitivity of NMR signals by several orders of magnitude, enabling otherwise impossible experiments. Unfortunately, the enhancements obtained at high magnetic fields (> 9 T) are only a small fraction of the theoretical limit due to the fact that current DNP mechanisms, including the cross effect...
In recent years magic angle spinning - dynamic nuclear polarization (MAS-DNP) developed as an excellent approach for boosting the sensitivity of solid state NMR (ssNMR) spectroscopy, thereby enabling the characterization of challenging systems in biology and chemistry. Most commonly, MAS-DNP is based on the use of nitroxide biradicals as polarizing agents. In materials science, since the use...
Specific Cross-Relaxation Enhancement by Active Motions under DNP (SCREAM-DNP) is a method which relies on direct polarization transfer in solid-state DNP at typical DNP temperatures.[1] The mechanism is based on cross relaxation between 1H and 13C. It is generated by the internal dynamics of methyl groups resulting in negative enhancement and inverted ...
Aiming at the design of an allosteric modulator of the neonatal Fc receptor (FcRn)–Immunoglobulin G (IgG) interaction, we developed a new methodology including NMR fragment screening, X-ray crystallography, and magic-angle-spinning (MAS) NMR at 100 kHz after sedimentation, exploiting very fast spinning of the nondeuterated soluble 42 kDa receptor construct to obtain resolved proton-detected 2D...
So-called phase-space representations such as Wigner functions, are a powerful tool for representing quantum states and characterizing their time evolution in the case of infinite-dimensional quantum systems and have been widely used in quantum optics and beyond. Continuous phase spaces have also been studied for the finite-dimensional quantum systems of individual spins. However, much less...
DNP in liquids is driven by electron-nuclear cross-relaxation, known as Overhauser effect (O-DNP). When relaxation is dominated by scalar hyperfine interaction, the enhancements can reach three orders of magnitudes, as recently reported for $^{13}$C-DNP at 3.4 T [1].
Hereby we present a systematic study performed at different magnetic fields on model systems doped with nitroxide radical...