Statistics of protein electrostatics.

Molecular dynamics simulations of a small redox-active protein plastocyanin address two questions. (i) Do protein electrostatics equilibrate to the Gibbsian ensemble? (ii) Do the electrostatic potential and electric field inside proteins follow the Gaussian distribution? The statistics of electrostatic potential and electric field are probed by applying small charge and dipole perturbations to different sites within the protein. Nonergodic (non-Gibbsian) sampling is detectable through violations of exact statistical rules constraining the first and second statistical moments (fluctuation-dissipation relations) and the linear relation between free-energy surfaces of the collective coordinate representing the Hamiltonian electrostatic perturbation.

The aquastatin biosynthetic gene cluster encodes a versatile polyketide synthase capable of synthesising heteromeric depsides with diverse alkyl side chains.

Depsides have garnered substantial interest due to the diverse biological activities exhibited by members of this class. Among these are the antibacterial aquastatins, glycosylated heteromeric depsides formed through the condensation of orsellinic acid with corticiolic acid. In this work, we isolated aquastatins and the recently described geministatins, along with several novel aquastatin-related depsides with different alkyl side chains from the fungus MST-FP2131.

A near-complete genome of the uncultured phage COMBAT-CF_PAR1 isolated from the lungs of an infant with cystic fibrosis.

In cystic fibrosis, bacteria-bacteriophage interaction in the lower airways is poorly understood. We present the near-complete genome of the uncultured Siphovirus-like bacteriophage, phage COMBAT-CF_PAR1, isolated from the lower airways. The genome spans 41,510 bp with 33.

Post-CCSD(T) Thermochemistry of Chlorine Fluorides as a Challenging Test Case for Evaluating Density Functional Theory and Composite Ab Initio Methods.

Quantum chemistry plays a key role in exploring the chemical properties of highly reactive chlorine polyfluoride compounds (ClF). Here, we investigate the thermochemical properties of ClF species (n=2-6) by means of high-level thermochemical procedures approximating the CCSDT(Q) and CCSDTQ5 energies at the complete basis set limit. We consider total atomization energies (TAEs), Cl-F bond dissociation energies (BDEs), F elimination energies (F elim.

Macronutrients in Human Milk and Early Childhood Growth-Is Protein the Main Driver?

Background: Infant growth trajectories reflect current health status and may predict future obesity and metabolic diseases. Human milk is tailored to support optimal infant growth. However, nutrient intake rather than milk composition more accurately predicts growth outcomes.

Anticancer Activity of Vitamin D, Lumisterol and Selected Derivatives against Human Malignant Melanoma Cell Lines.

Despite the recent development of improved methods of treating melanoma such as targeted therapy, immunotherapy or combined treatment, the number of new cases worldwide is increasing. It is well known that active metabolites of vitamin D and lumisterol (L) exert photoprotective and antiproliferative effects on the skin, while UV radiation is a major environmental risk factor for melanoma. Thus, many natural metabolites and synthetic analogs of steroidal and secosteroidal molecules have been tested on various cancer cells and in animal models.

Methods to analyze mitochondrial protein translocation in plant mitochondria.

Complex processes have evolved in plants to import proteins into mitochondria. Investigating these processes in plants provides insights into the specialised machinery and pathways that have evolved to cope with; (1) the immobile nature of plants that results in exposure to environmental stresses, and (2) the more complex cell environment due to the presence of plastids, the most prevalent being chloropalst in leaves. In this chapter, we present detailed protocols for the isolation of respiratory competent, coupled mitochondria from Arabidopsis thaliana, conducting protein import assays, and analyzing protein assembly into large multi-subunit complexes.

Epigenome-wide analysis across the development span of pediatric acute lymphoblastic leukemia: backtracking to birth.

Background: Cancer is the leading cause of disease-related mortality in children. Causes of leukemia, the most common form, are largely unknown. Growing evidence points to an origin in-utero, when global redistribution of DNA methylation occurs driving tissue differentiation.

Parallel molecular data storage by printing epigenetic bits on DNA.

DNA storage has shown potential to transcend current silicon-based data storage technologies in storage density, longevity and energy consumption. However, writing large-scale data directly into DNA sequences by de novo synthesis remains uneconomical in time and cost. We present an alternative, parallel strategy that enables the writing of arbitrary data on DNA using premade nucleic acids.

Finding the E-channel proton loading sites by calculating the ensemble of protonation microstates.

The aerobic electron transfer chain builds a proton gradient by proton coupled electron transfer reactions through a series of proteins. Complex I is the first enzyme in the sequence. Here transfer of two electrons from NADH to quinone yields four protons pumped from the membrane N- (negative, higher pH) side to the P- (positive, lower pH) side.

When a Twist Makes a Difference: Exploring PCET and ESIPT on a Nonplanar Hydrogen-Bonded Donor-Acceptor System.

Bioinspired benzimidazole-phenol constructs with an intramolecular hydrogen bond connecting the phenol and the benzimidazole have been synthesized to study both proton-coupled electron transfer (PCET) and excited-state intramolecular proton transfer (ESIPT) processes. Strategic incorporation of a methyl group disrupts the coplanarity between the aromatic units, causing a pronounced twist, weakening the intramolecular hydrogen bond, decreasing the phenol redox potential, reducing the chemical reversibility, and quenching the fluorescence emission. Infrared spectroelectrochemistry and transient absorption spectroscopy confirm the formation of the oxidized product upon PCET and probe excited-state relaxation mechanisms, respectively.

Experimental and Computational Studies of Steric Factors in the Isomerization of Internal Alkynes within the Coordination Environment of Half-Sandwich Metal Complexes.

The isomerization of internal alkynes ArC≡CAr within the coordination environment of low-valent half-sandwich [Ru(dppe)Cp] complexes via a 1,2-migration process affords vinylidene species [Ru{=C=C(Ar)Ar}(dppe)Cp]. The rearrangement reactions of symmetrically and asymmetrically substituted substrates featuring different electron-donating and -withdrawing groups and of varying steric bulk were modelled using density functional theory (DFT), and the conclusions supported by experimental observations. Examination of the reaction pathway and associated activation barriers reveal a high solvent dependency for the generation of the key intermediate species [Ru(dppe)Cp] from [RuCl(dppe)Cp] by halide dissociation in the presence of Na salts of weakly coordinating anions, with the lattice enthalpy of the NaCl by-product playing a critical role in the overall thermochemical balance of the reaction.

Hairygami: Analysis of DNA Nanostructures' Conformational Change Driven by Functionalizable Overhangs.

DNA origami is a widely used method to construct nanostructures by self-assembling designed DNA strands. These structures are often used as "pegboards" for templated assembly of proteins, gold nanoparticles, aptamers, and other molecules, with applications ranging from therapeutics and diagnostics to plasmonics and photonics. Imaging these structures using atomic force microscopy (AFM) or transmission electron microscope (TEM) does not capture their full conformation ensemble as they only show their shape flattened on a surface.

Putting the squeeze on valence tautomerism in cobalt-dioxolene complexes.

Molecules that can reversibly switch between electronic states under an external stimulus are of interest to numerous applications. Complexes of open shell metal ions with redox active ligands undergo valence tautomerism, resulting in magnetic, colour and structural switching, relevant to data storage and actuators. However, the precise structural changes occurring during valence tautomerism in the solid state are unclear due to the lack of atomic-resolution characterization.

Photocatalytic overall water splitting endowed by modulation of internal and external energy fields.

The pursuit of sustainable and clean energy sources has driven extensive research into the generation and use of novel energy vectors. The photocatalytic overall water splitting (POWS) reaction has been identified as a promising approach for harnessing solar energy to produce hydrogen to be used as a clean energy carrier. Materials chemistry and associated photocatalyst design are key to the further improvement of the efficiency of the POWS reaction through the optimization of charge carrier separation, migration and interfacial reaction kinetics.

Synthesis, Structure, and Redox Properties of Nonsymmetric 6-Oxoverdazyls.

Nonsymmetric 6π-electron ("oxidized") 6-oxoverdazyls have been synthesized for the first time. After formal incorporation of a hydrogen atom, the corresponding 7π-electron neutral verdazyl radical is generated. The 7π radical can undergo a further electrochemically reversible reduction to an 8π anion.

Structural mechanism of HP1⍺-dependent transcriptional repression and chromatin compaction.

Heterochromatin protein 1 (HP1) plays a central role in establishing and maintaining constitutive heterochromatin. However, the mechanisms underlying HP1-nucleosome interactions and their contributions to heterochromatin functions remain elusive. Here, we present the cryoelectron microscopy (cryo-EM) structure of an HP1α dimer bound to an H2A.

A Longitudinal Observation of Antenatal Milk Expression in Mothers of Infants with Congenital Anomalies.

For mothers of infants with congenital anomalies, antenatal milk expression (AME), known as hand expression during late pregnancy, allows mothers to contribute to their newborn's care through colostrum collection. However, research is limited by self-report of AME adherence and colostrum volume. This study examined the ability of participants to adhere to a recommended protocol on AME for any removal and measurement of colostrum during late pregnancy.

Periodic diffraction from an aperiodic monohedral tiling - the Spectre tiling. Addendum.

This article describes the diffraction pattern (2-periodic Fourier transform) from the vertices of a large patch of the recently discovered `Spectre' tiling - a strictly chiral aperiodic monotile. It was reported recently that the diffraction pattern of the related weakly chiral aperiodic `Hat' monotile was 2-periodic with chiral plane-group symmetry p6 [Kaplan et al. (2024).

Mechanochemically responsive polymer enables shockwave visualization.

Understanding the physical and chemical response of materials to impulsive deformation is crucial for applications ranging from soft robotic locomotion to space exploration to seismology. However, investigating material properties at extreme strain rates remains challenging due to temporal and spatial resolution limitations. Combining high-strain-rate testing with mechanochemistry encodes the molecular-level deformation within the material itself, thus enabling the direct quantification of the material response.