Disorder-to-order active site capping regulates the rate-limiting step of the inositol pathway.

Myo-inositol-1-phosphate synthase (MIPS) catalyzes the NAD+-dependent isomerization of glucose-6-phosphate (G6P) into inositol-1-phosphate (IMP), controlling the rate-limiting step of the inositol pathway. Previous structural studies focused on the detailed molecular mechanism, neglecting large-scale conformational changes that drive the function of this 240 kDa homotetrameric complex. In this study, we identified the active, endogenous MIPS in cell extracts from the thermophilic fungus Thermochaetoides thermophila. By resolving the native structure at 2.48 Å (FSC = 0.143), we revealed a fully populated active site. Utilizing 3D variability analysis, we uncovered conformational states of MIPS, enabling us to directly visualize an order-to-disorder transition at its catalytic center. An acyclic intermediate of G6P occupied the active site in two out of the three conformational states, indicating a catalytic mechanism where electrostatic stabilization of high-energy intermediates plays a crucial role. Examination of all isomerases with known structures revealed similar fluctuations in secondary structure within their active sites. Based on these findings, we established a conformational selection model that governs substrate binding and eventually inositol availability. In particular, the ground state of MIPS demonstrates structural configurations regardless of substrate binding, a pattern observed across various isomerases. These findings contribute to the understanding of MIPS structure-based function, serving as a template for future studies targeting regulation and potential therapeutic applications.

IT-Related Barriers and Facilitators to the Implementation of a New European eHealth Solution, the Digital Survivorship Passport (SurPass Version 2.0): Semistructured Digital Survey.

BACKGROUND: To overcome knowledge gaps and optimize long-term follow-up (LTFU) care for childhood cancer survivors, the concept of the Survivorship Passport (SurPass) has been invented. Within the European PanCareSurPass project, the semiautomated and interoperable SurPass (version 2.0) will be optimized, implemented, and evaluated at 6 LTFU care centers representing 6 European countries and 3 distinct health system scenarios: (1) national electronic health information systems (EHISs) in Austria and Lithuania, (2) regional or local EHISs in Italy and Spain, and (3) cancer registries or hospital-based EHISs in Belgium and Germany. OBJECTIVE: We aimed to identify and describe barriers and facilitators for SurPass (version 2.0) implementation concerning semiautomation of data input, interoperability, data protection, privacy, and cybersecurity. METHODS: IT specialists from the 6 LTFU care centers participated in a semistructured digital survey focusing on IT-related barriers and facilitators to SurPass (version 2.0) implementation. We used the fit-viability model to assess the compatibility and feasibility of integrating SurPass into existing EHISs. RESULTS: In total, 13/20 (65%) invited IT specialists participated. The main barriers and facilitators in all 3 health system scenarios related to semiautomated data input and interoperability included unaligned EHIS infrastructure and the use of interoperability frameworks and international coding systems. The main barriers and facilitators related to data protection or privacy and cybersecurity included pseudonymization of personal health data and data retention. According to the fit-viability model, the first health system scenario provides the best fit for SurPass implementation, followed by the second and third scenarios. CONCLUSIONS: This study provides essential insights into the information and IT-related influencing factors that need to be considered when implementing the SurPass (version 2.0) in clinical practice. We recommend the adoption of Health Level Seven Fast Healthcare Interoperability Resources and data security measures such as encryption, pseudonymization, and multifactor authentication to protect personal health data where applicable. In sum, this study offers practical insights into integrating digital health solutions into existing EHISs.

Aqueous Ionic Liquid Mixtures as Minimal Models of Lipid Bilayer Membranes.

We introduce aqueous ionic liquid (IL) mixtures, specifically mixtures of 1-butyl-3-imidazoliumtetrafluoroborate (BMImBF4), with water as a minimal model of lipid bilayer membranes. Imidazolium-based ILs are known to form clustered nanoscale structures in which local inhomogeneities, micellar or lamellar structures, are formed to shield hydrophobic parts of the cation from the polar cosolvent (water). To investigate these nanostructures, dynamic light scattering (DLS) on samples with different mixing ratios of water and BMImBF4 was performed. At mixing ratios of 50% and 45% (v/v), small and homogeneous nanostructures can indeed be detected. To test whether, in particular, these stable nanostructures in aqueous mixtures may mimic the effects of phospholipid bilayer membranes, we further investigated their interaction with myelin basic protein (MBP), a peripheral, intrinsically disordered membrane protein of the myelin sheath. Using dynamic light scattering (DLS), continuous wave (CW) and pulse electron paramagnetic resonance (EPR), and small-angle X-ray scattering (SAXS) on recombinantly produced, "healthy" charge variants rmC1WT and double cysteine variant C1S17CH85C, we find that the size and the shape of the determined nanostructures in an optimum mixture offer model membranes in which the protein exhibits native behavior. SAXS measurements illuminate the size and shape of the nanostructures and indicate IL-rich "beads" clipped together by functional MBP, one of the in vivo roles of the protein in the myelin sheath. All the gathered data combined indicate that the 50% and 45% aqueous IL mixtures can be described as offering minimal models of a lipid mono- or bilayer that allow native processing and potential study of at least peripheral membrane proteins like MBP.