Eugenio Daviso - Academia.edu (original) (raw)

Papers by Eugenio Daviso

Vaccines

The COVID-19 pandemic has revealed a crucial need for rapid, straightforward collection and testi... more The COVID-19 pandemic has revealed a crucial need for rapid, straightforward collection and testing of biological samples. Serological antibody assays can analyze patient blood samples to confirm immune response following mRNA vaccine administration or to verify past exposure to the SARS-CoV-2 virus. While blood tests provide vital information for clinical analysis and epidemiology, sample collection is not trivial; this process requires a visit to the doctor’s office, a professionally trained phlebotomist to draw several milliliters of blood, processing to yield plasma or serum, and necessitates appropriate cold chain storage to preserve the specimen. A novel whole blood collection kit (truCOLLECT) allows for a lancet-based, decentralized capillary blood collection of metered low volumes and eliminates the need for refrigerated transport and storage through the process of active desiccation. Anti-SARS-CoV-2 spike (total and neutralizing) and nucleocapsid protein antibody titers in ...

The Journal of Physical Chemistry B

The sensitivity enhancements available from dynamic nuclear polarization (DNP) are rapidly reshap... more The sensitivity enhancements available from dynamic nuclear polarization (DNP) are rapidly reshaping the research landscape and expanding the field of nuclear magnetic resonance (NMR) spectroscopy as a tool for solving complex chemical and structural problems. The past decade

All in-text references underlined in blue are linked to publications on ResearchGate, letting you... more All in-text references underlined in blue are linked to publications on ResearchGate, letting you access and read them immediately.

Journal of Biomolecular NMR, Jan 19, 2013

Resonance assignment is the first step in NMR structure determination. For magic angle spinning N... more Resonance assignment is the first step in NMR structure determination. For magic angle spinning NMR, this is typically achieved with a set of heteronuclear correlation experiments (NCaCX, NCOCX, CONCa) that utilize SPECIFIC-CP 15 N-13 C transfers. However, the SPECIFIC-CP transfer efficiency is often compromised by molecular dynamics and probe performance. Here we show that one-bond ZF-TEDOR 15 N-13 C transfers provide simultaneous NCO and NCa transfers with at least as much sensitivity as SPECIFIC-CP for some non-crystalline samples. Furthermore, a 3D TEDOR-CC experiment provides heteronuclear sidechains correlations and robustness with respect to proton decoupling and radiofrequency power instabilities. We demonstrate transfer efficiencies and connectivities by application of 3D ZF-TEDOR-DARR to a model microcrystalline protein, GB1, and a less ideal system, GvpA in intact gas vesicles.

Ó The Author(s) 2009. This article is published with open access at Springerlink.com Abstract Pho... more Ó The Author(s) 2009. This article is published with open access at Springerlink.com Abstract Photochemically induced dynamic nuclear polarization magic-angle spinning nuclear magnetic resonance (photo-CIDNP MAS NMR) allows for the investigation of the electronic structure of the photochemical machinery of photosynthetic reaction centers (RCs) at atomic resolution. For such experiments, either continuous radiation from white xenon lamps or green laser pulses are applied to optically dense samples. In order to explore their optical properties, optically thick samples of isolated and quinone-removed RCs of the purple bacteria of Rhodobacter sphaeroides wild type are studied by nanosecond laser-flash 13 C photo-CIDNP MAS NMR using excitation wavelengths between 720 and 940 nm. Action spectra of both the transient nuclear polarization as well as the nuclear hyperpolarization, remaining in the electronic ground state at the end of the photocycle, are obtained. It is shown that the signal...

Tumor biopsies are commonly formalin-fixed and paraffin-embedded (FFPE) for long-term and efficie... more Tumor biopsies are commonly formalin-fixed and paraffin-embedded (FFPE) for long-term and efficient storage. However, FFPE preservation can greatly compromise the quality of samples, the extraction of nucleic acids, and feasibility of downstream studies, including RNA sequencing. These challenges are especially evident in the studies of clinical trial samples, where the sizes of biopsies often limit the amount of material available for study. Here, we evaluate two nucleic acid extraction kits (Covaris truXTRAC FFPE tNA Plus, QIAGEN miRNeasy FFPE) and three hybridized-capture-based RNA sequencing library preparations (Agilent SureSelect XT RNA Direct, Agilent SureSelect XT HS, and Illumina TruSeq RNA Exome) to evaluate the impact of these sample processing steps on transcriptome evaluation in a melanoma biopsy procured in a clinical setting and preserved by FFPE. While there exist many options for extraction and library preparation that are appropriate for RNA sequencing from FFPE sa...

Journal of the American Chemical Society, Jan 28, 2018

Despite much attention, the path of the highly consequential primary proton transfer in the light... more Despite much attention, the path of the highly consequential primary proton transfer in the light-driven ion pump bacteriorhodopsin (bR) remains mysterious. Here we use DNP-enhanced magic angle spinning (MAS) NMR to study critical elements of the active site just before the Schiff base (SB) deprotonates (in the L intermediate), immediately after the SB has deprotonated and Asp85 has become protonated (in the Mo intermediate), and just after the SB has reprotonated and Asp96 has deprotonated (in the N intermediate). An essential feature that made these experiments possible is the 75-fold signal enhancement through DNP. 15N(SB)-1H correlations reveal that the newly deprotonated SB is accepting a hydrogen bond from an alcohol and 13C-13C correlations show that Asp85 draws close to Thr89 before the primary proton transfer. Concurrently, 15N-13C correlations between the SB and Asp85 show that helices C and G draw closer together just prior to the proton transfer and relax thereafter. Tog...

The journal of physical chemistry. B, Jan 18, 2017

In DNP MAS NMR experiments at ∼80-110 K, the structurally important -(13)CH3 and -(15)NH3(+) sign... more In DNP MAS NMR experiments at ∼80-110 K, the structurally important -(13)CH3 and -(15)NH3(+) signals in MAS spectra of biological samples disappear due to the interference of the molecular motions with the (1)H decoupling. Here we investigate the effect of these dynamic processes on the NMR line shapes and signal intensities in several typical systems: (1) microcrystalline APG, (2) membrane protein bR, (3) amyloid fibrils PI3-SH3, (4) monomeric alanine-CD3, and (5) the protonated and deuterated dipeptide N-Ac-VL over 78-300 K. In APG, the three-site hopping of the Ala-Cβ peak disappears completely at 112 K, concomitant with the attenuation of CP signals from other (13)C's and (15)N's. Similarly, the (15)N signal from Ala-NH3(+) disappears at ∼173 K, concurrent with the attenuation in CP experiments of other (15)N's as well as (13)C's. In bR and PI3-SH3, the methyl groups are attenuated at ∼95 K, while all other (13)C's remain unaffected. However, both systems exh...

TrAC Trends in Analytical Chemistry, 2016

Abstract NMR relaxometry is a powerful technique used to study and measure the relaxation rates o... more Abstract NMR relaxometry is a powerful technique used to study and measure the relaxation rates of nuclear spins in complex environments. The relaxation rates depend strongly on the mobility of the microscopic environment and the strength of the applied magnetic field. T2 Biosystems has developed the T2 Magnetic Resonance (T2MR) platform, which enables the detection and measurement of a variety of diagnostic targets, including molecular targets (DNA, RNA), immunodiagnostics (proteins, small molecules) and a broad range of functional hemostasis measurements. This methodology enables a first-in-class, fully-automated test for fungal sepsis and has a limit of detection as low as 1 CFU/mL, compared to the 100 to 1,000 CFU/mL achieved by PCR-based in vitro diagnostics. Results indicate this sensitive and rapid test may significantly reduce the high mortality and the high cost of care for Candida infections. T2MR technology is also being used investigationally to evaluate hemostasis disorders, which require diagnostic identification and monitoring for both acute and chronic conditions that range from traumatic injury to routine monitoring of anticoagulant therapy, evaluation of clotting diseases and evaluation of bleeding disorders.T2MR measurements enable a comprehensive assessment of a patient's hemostasis status by determining multiple parameters including clotting times, platelet function, fibrinogen, and fibrinolysis from a single sample with data analysis beginning in as short as 5 minutes at the point of care using just 40 microliters of blood. By providing a rapid and accurate global assessment of a patient's hemostasis state, T2MR has the potential to significantly assist with the active management of hemostasis disorders while reducing both healthcare costs and mortality.

Photosynthesis. Energy from the Sun, 2008

Abstract RCs of Rhodobacter sphaeroides wildtype (WT) and the carotenoid-less mutant R26 have bee... more Abstract RCs of Rhodobacter sphaeroides wildtype (WT) and the carotenoid-less mutant R26 have been investigated by 15N photo-CIDNP MAS NMR. In both cases, the dimeric structure of the special pair in the radical cation state and the involve-ment of the ...

Journal of magnetic resonance (San Diego, Calif. : 1997), 2014

In solid-state photochemically induced dynamic nuclear polarization (photo-CIDNP) MAS NMR experim... more In solid-state photochemically induced dynamic nuclear polarization (photo-CIDNP) MAS NMR experiments, strong signal enhancement is observed from molecules forming a spin-correlated radical pair in a rigid matrix. Two-dimensional (13)C-(13)C dipolar-assisted rotational resonance (DARR) photo-CIDNP MAS NMR experiments have been applied to obtain exact chemical shift assignments from those cofactors. Under continuous illumination, the signals are enhanced via three-spin mixing (TSM) and differential decay (DD) and their intensity corresponds to the electron spin density in pz orbitals. In multiple-(13)C labelled samples, spin diffusion leads to propagation of signal enhancement to all (13)C spins. Under steady-state conditions, direct signal assignment is possible due to the uniform signal intensity. The original intensities, however, are inaccessible and the information of the local electron spin density is lost. Upon laser-flash illumination, the signal is enhanced via the classical...

The Journal of Physical Chemistry C, 2009

The solid-state photo-CIDNP effect is known to occur in natural photosynthetic reaction centers (... more The solid-state photo-CIDNP effect is known to occur in natural photosynthetic reaction centers (RCs) where it can be observed by magic-angle spinning (MAS) NMR as strong modification of signal intensities under illumination compared to experiments performed in the dark. ...

The Journal of Physical Chemistry B, 2011

Sugar-derived humins and melanoidins figure significantly in food chemistry, agricultural chemist... more Sugar-derived humins and melanoidins figure significantly in food chemistry, agricultural chemistry, biochemistry and prebiotic chemistry. Despite wide interest and significant experimental attention, the amorphous and insoluble nature of the polymers has made them resistant to conventional structural characterization. Here we make use of solid-state NMR methods, including selective 13 C substitution, 1 H-dephasing, and double quantum filtration. The spectra, and their interpretation, are simplified by relying exclusively on hydronium for catalysis. The results for polymers derived from ribose, deoxyribose and fructose indicate diverse pathways to furans, suggest a simple route to pyrroles in the presence of amines, and reveal a heterogenous network-type polymer in which sugar molecules cross-link the heterocycles.

Photosynthesis Research, 2010

Journal of the American Chemical Society, 2011

Several techniques rely on electron-nuclear interactions to boost the polarization of nuclear spi... more Several techniques rely on electron-nuclear interactions to boost the polarization of nuclear spins in the solid phase. Averaging out of anisotropic interactions as a result of molecular tumbling strongly reduces the applicability of such hyperpolarization approaches in liquids. Here we show for the first time that anisotropic electron-nuclear interactions in solution can survive sufficiently long to generate nuclear spin polarization by the solid-state photo-CIDNP mechanism. A 10,000-fold NMR signal increase in solution was observed for a giant biomolecular complex of a photosynthetic membrane protein with a tumbling correlation time in the submicrosecond regime, corresponding to a molecular weight close to 1 MDa.

The Journal of Physical Chemistry Letters, 2012

Oxygen-17 detected DNP NMR of a water/glycerol glass enabled an 80-fold enhancement of signal int... more Oxygen-17 detected DNP NMR of a water/glycerol glass enabled an 80-fold enhancement of signal intensities at 82 K, using the biradical TOTAPOL. The >6,000-fold savings in acquisition time enables 17 O-1 H distance measurements and heteronuclear correlation experiments. These experiments are the initial demonstration of the feasibility of DNP NMR on quadrupolar 17 O.