Beyond brain injury: Examining the neuropsychological and psychosocial sequelae of post-traumatic epilepsy.

Objective: This study investigates neuropsychological and psychosocial outcomes in patients with traumatic brain injury (TBI) and post-traumatic epilepsy (PTE) compared to a healthy control group.

Method: Utilizing a quasi-experimental cross-sectional design, the research involved patients with TBI and PTE referred from a Taiwanese medical center. An age- and education-matched control group of healthy adults without traumatic injuries was also recruited.

Location of the cross-β structure in prion fibrils: A search by seeding and electron spin resonance spectroscopy.

Prion diseases are transmissible fatal neurodegenerative disorders spreading between humans and other mammals. The pathogenic agent, prion, is a protease-resistant, β-sheet-rich protein aggregate, converted from a membrane protein called PrP . PrP is the misfolded form of PrP and undergoes self-propagation to form the infectious amyloids.

Protein Stability Depends Critically on the Surface Hydrogen-Bonding Network: A Case Study of Bid Protein.

Understanding how proteins retain structural stability is not only of fundamental importance in biophysics but also critical to industrial production of antibodies and vaccines. Protein stability is known to depend mainly on two effects: internal hydrophobicity and H-bonding between the protein surface and solvent. A challenging task is to identify their individual contributions to a protein.

Nitrosylation of the Diiron Core Mediated by the N Domain of YtfE.

The YtfE protein catalyzes the reduction of NO to NO, protecting iron-sulfur clusters from nitrosylation. The structure of YtfE has a two-domain architecture, with a diiron-containing C-terminal domain linked to an N-terminal domain, in which the function of the latter is enigmatic. Here, by using electron spin resonance (ESR) spectroscopy, we show that YtfE exists in two conformational states, one of which has not been reported.

Identifying Protein Conformational Dynamics Using Spin-label ESR.

Spin-label electron spin resonance (ESR) has emerged as a powerful tool to characterize protein dynamics. One recent advance is the development of ESR for resolving dynamical components that occur or coexist during a biological process. It has been applied to study the complex structural and dynamical aspects of membranes and proteins, such as conformational changes in protein during translocation from cytosol to membrane, conformational exchange between equilibria in response to protein-protein and protein-ligand interactions in either soluble or membrane environments, protein oligomerization, and temperature- or hydration-dependent protein dynamics.

Slow Dynamics around a Protein and Its Coupling to Solvent.

Solvent is essential for protein dynamics and function, but its role in regulating the dynamics remains debated. Here, we employ saturation transfer electron spin resonance (ST-ESR) to explore the issue and characterize the dynamics on a longer (from μs to s) time scale than has been extensively studied. We first demonstrate the reliability of ST-ESR by showing that the dynamical changeovers revealed in the spectra agree to liquid-liquid transition (LLT) in the state diagram of the glycerol/water system.

Study of Protein Dynamics under Nanoconfinement by Spin-Label ESR: A Case of T4 Lysozyme Protein.

The electron spin resonance (ESR) spectra of spin-labeled proteins are sensitive to dynamics, but discrimination between the various dynamics is often difficult. Here, we report an improvement in ESR spectral sensitivity to local backbone dynamics of a protein by a methodology that performs ESR measurement when the protein is confined in the nanochannels of a mesoporous material. An extensive set of ESR data, which includes the spectra of a nitroxide-based side chain from buried and solvent-exposed sites of a T4 lysozyme (T4L) protein, were obtained over a range of temperatures, 200-300 K, to explore the dynamics of T4L under nanoconfinement.

Revealing structural changes of prion protein during conversion from α-helical monomer to β-oligomers by means of ESR and nanochannel encapsulation.

Under nondenaturing neutral pH conditions, full-length mouse recombinant prion protein lacking the only disulfide bridge can spontaneously convert from an α-helical-dominant conformer (α-state) to a β-sheet-rich conformer (β-state), which then associates into β-oligomers, and the kinetics of this spontaneous conversion depends on the properties of the buffer used. The molecular details of this structural conversion have not been reported due to the difficulty of exploring big protein aggregates. We introduced spin probes into different structural segments (three helices and the loop between strand 1 and helix 1), and employed a combined approach of ESR spectroscopy and protein encapsulation in nanochannels to reveal local structural changes during the α-to-β transition.

Concurrent observation of bulk and protein hydration water by spin-label ESR under nanoconfinement.

Under nanoconfinement the formation of crystalline ice is suppressed, allowing the study of water dynamics at subfreezing temperatures. Here we report a temperature-dependent investigation (170-260 K) of the behavior of hydration water under nanoconfinement by ESR techniques. A 26-mer-long peptide and the Bax protein are studied.