The structural organisation of pentraxin-3 and its interactions with heavy chains of inter-α-inhibitor regulate crosslinking of the hyaluronan matrix.

Pentraxin-3 (PTX3) is an octameric protein, comprised of eight identical protomers, that has diverse functions in reproductive biology, innate immunity and cancer. PTX3 interacts with the large polysaccharide hyaluronan (HA) to which heavy chains (HCs) of the inter-α-inhibitor (IαI) family of proteoglycans are covalently attached, playing a key role in the (non-covalent) crosslinking of HC•HA complexes. These interactions stabilise the cumulus matrix, essential for ovulation and fertilisation in mammals, and are also implicated in the formation of pathogenic matrices in the context of viral lung infections.

Molecular Dynamics Simulation for Membrane Fusion.

The soluble N-ethylmaleimide sensitive factor attachment protein receptor (SNARE) protein complex drives membrane fusion, and this process is further aided by accessory proteins, including complexin and α-synuclein. To understand the molecular mechanism underlying membrane fusion, we introduce an all-atom molecular dynamics (MD) simulation method. This method is used to understand and predict the conformations of protein and lipids, membrane geometry, and their interaction at femtosecond precision, by describing complex chemical systems with atomic models.

Single-molecule localisation microscopy (SMLM) is feasible in human and animal formalin fixed paraffin embedded (FFPE) tissues in medical renal disease.

Aims: Establishment of a protocol for routine single-molecule localisation microscopy (SMLM) imaging on formalin fixed paraffin embedded (FFPE) tissue using medical renal disease including minimal change disease (MCD) and focal segmental glomerulosclerosis (FSGS).

Methods: Protocol for normal and diseased renal FFPE tissue was developed to investigate the clinical diagnostic potential of SMLM. Antibody concentrations were determined for confocal microscopy and transferred to SMLM.

Systematic review: differences in complete blood count component rhythms.

Study Objectives: The complete blood count (CBC) is one of the most commonly ordered blood tests with a large range of reference values that does not consider time of day for interpretation. Our objective was to systematically review this topic to report on peak and trough timing of CBC values.

Methods: A systematic search was performed for studies evaluating any component of the CBC with at least three collections over 24 hours.

Alternating Cellular Functions by Optogenetic Control of Organelles.

Organelles play essential roles in cellular homeostasis and various cellular functions in eukaryotic cells. The current experimental strategy to modulate organelle functions is limited due to the dynamic nature and subcellular distribution of organelles in live cells. Optogenetics utilizes photoactivatable proteins to enable dynamic control of molecular activities through visible light.

Biophysical Analysis of Therapeutic Antibodies in the Early Development Pipeline.

The successful progression of therapeutic antibodies and other biologics from the laboratory to the clinic depends on their possession of "drug-like" biophysical properties. The techniques and the resultant biophysical and biochemical parameters used to characterize their ease of manufacture can be broadly defined as developability. Focusing on antibodies, this review firstly discusses established and emerging biophysical techniques used to probe the early-stage developability of biologics, aimed towards those new to the field.

Kinetic Analysis of Cyclization by the Substrate-Tolerant Lanthipeptide Synthetase ProcM.

Lanthipeptides are ribosomally synthesized and post-translationally modified peptides (RiPPs) characterized by the presence of thioether cross-links called lanthionine and methyllanthionine, formed by dehydration of Ser/Thr residues and Michael-type addition of Cys side chains onto the resulting dehydroamino acids. Class II lanthipeptide synthetases are bifunctional enzymes responsible for both steps, thus generating macrocyclic natural products. ProcM is part of a group of class II lanthipeptide synthetases that are known for their remarkable substrate tolerance, having large numbers of natural substrates with highly diverse peptide sequences.

Biological hallmarks of systemic sclerosis are present in the skin and serum of patients with Very Early Diagnosis of SSc (VEDOSS).

Objective: The Very Early Diagnosis of Systemic Sclerosis (VEDOSS) EUSTAR study showed that, despite not showing any clinical sign of disease, patients with Raynaud's and antinuclear antibodies and/or capillaroscopy abnormalities often progress to systemic sclerosis (SSc) within 5 years. We aimed to determine whether VEDOSS biosamples show biological SSc activity pre-clinically.

Methods: Skin biopsies were histologically analysed.

Targeting ERBB3 and AKT to overcome adaptive resistance in EML4-ALK-driven non-small cell lung cancer.

The fusion event between EML4 and ALK drives a significant oncogenic activity in 5% of non-small cell lung cancer (NSCLC). Even though potent ALK-tyrosine kinase inhibitors (ALK-TKIs) are successfully used for the treatment of EML4-ALK-positive NSCLC patients, a subset of those patients eventually acquire resistance during their therapy. Here, we investigate the kinase responses in EML4-ALK V1 and V3-harbouring NSCLC cancer cells after acute inhibition with ALK TKI, lorlatinib (LOR).

Rationalizing mAb Candidate Screening Using a Single Holistic Developability Parameter.

A framework for the rational selection of a minimal suite of nondegenerate developability assays (DAs) that maximize insight into candidate developability or storage stability is lacking. To address this, we subjected nine formulation:mAbs to 12 mechanistically distinct DAs together with measurement of their accelerated and long-term storage stability. We show that it is possible to identify a reduced set of key variables from this suite of DAs by using orthogonal statistical methods.

Corrigendum: Long-term exposure to BAY2416964 reduces proliferation, migration and recapitulates transcriptional changes induced by AHR loss in PyMT-induced mammary tumor cells.

[This corrects the article DOI: 10.3389/fonc.2024.

Constrained TACC3 peptidomimetics for a non-canonical protein-protein interface elucidate allosteric communication in Aurora-A kinase.

Peptidomimetic design for non-canonical interfaces is less well established than for α-helix and β-strand mediated protein-protein interactions. Using the TACC3/Aurora-A kinase interaction as a model, we developed a series of constrained TACC3 peptide variants with 10-fold increased binding potencies ( ) towards Aurora-A in comparison to the parent peptide. High-affinity is achieved in part by restricting the accessible conformational ensemble of the peptide leading to a more favourable entropy of binding.

Hydrogen-Deuterium Exchange Mass Spectrometry Reveals Mechanistic Insights into RNA Oligonucleotide-Mediated Inhibition of TDP-43 Aggregation.

Deposits of aggregated TAR DNA-binding protein 43 (TDP-43) in the brain are associated with several neurodegenerative diseases. It is well established that binding of RNA/DNA to TDP-43 can prevent TDP-43 aggregation, but an understanding of the structure(s) and conformational dynamics of TDP-43, and TDP-43-RNA complexes, is lacking, including knowledge of how the solution environment modulates these properties. Here, we address this challenge using hydrogen-deuterium exchange-mass spectrometry.

Hsp70-Hsp90 organising protein (HOP/STIP1) is required for KSHV lytic replication.

Kaposi's sarcoma-associated herpesvirus (KSHV) is a DNA virus that causes Kaposi's sarcoma, a cancer of endothelial origin. KSHV uses the activity of host molecular chaperones like Hsp70 and Hsp90 for the folding of host and viral proteins required for productive infection. Hsp70 and Hsp90 chaperones form proteostasis networks with several regulatory proteins known as co-chaperones.

Multiplex Genome Editing of Human Pluripotent Stem Cells Using Cpf1.

Targeted genome editing of human pluripotent stem cells (hPSCs) is critical for basic and translational research and can be achieved with site-specific endonucleases. Cpf1 (CRISPR from ) is a programmable DNA endonuclease with AT-rich PAM sequences. In this protocol, we describe procedures for using a single vector system to deliver Cpf1 and CRISPR RNA (crRNA) for genome editing in hPSCs.

Virus-modified paraspeckle-like condensates are hubs for viral RNA processing and their formation drives genomic instability.

The nucleus is a highly organised yet dynamic environment containing distinct membraneless nuclear bodies. This spatial separation enables a subset of components to be concentrated within biomolecular condensates, allowing efficient and discrete processes to occur which regulate cellular function. One such nuclear body, paraspeckles, are comprised of multiple paraspeckle proteins (PSPs) built around the architectural RNA, NEAT1_2.

Lymphocytic choriomeningitis arenavirus utilises intercellular connections for cell to cell spread.

The Arenaviridae family of segmented RNA viruses contains nearly 70 species with several associated with fatal haemorrhagic fevers, including Lassa, Lujo and Junin viruses. Lymphocytic choriomeningitis arenavirus (LCMV) is associated with fatal neurologic disease in humans and additionally represents a tractable model for studying arenavirus biology. Within cultured cells, a high proportion of LCMV spread is between directly neighbouring cells, suggesting infectivity may pass through intercellular connections, bypassing the canonical extracellular route involving egress from the plasma membrane.

Generating and validating renewable affimer protein binding reagents targeting SH2 domains.

Despite SH2 domains, being pivotal in protein interactions linked to various diseases like cancer, we lack specific research tools for intracellular assays. Understanding SH2-mediated interactions and creating effective inhibitors requires tools which target individual protein domains. Affimer reagents exhibit promise, yet their potential against the extensive SH2 domain family remains largely unexplored.

Capturing Dynamic Assembly of Nanoscale Proteins During Network Formation.

The structural evolution of hierarchical structures of nanoscale biomolecules is crucial for the construction of functional networks in vivo and in vitro. Despite the ubiquity of these networks, the physical mechanisms behind their formation and self-assembly remains poorly understood. Here, this study uses photochemically cross-linked folded protein hydrogels as a model biopolymer network system, with a combined time-resolved rheology and small-angle x-ray scattering (SAXS) approach to probe both the load-bearing structures and network architectures respectively thereby providing a cross-length scale understanding of the network formation.

Use of Affimer technology for inhibition of α2-antiplasmin and enhancement of fibrinolysis.

Hypofibrinolysis is a documented abnormality in conditions with high risk of vascular occlusion. A key inhibitor of fibrinolysis is α2-antiplasmin (α2AP), and we hypothesize that the Affimer technology, comprising small conformational proteins with 2 9-amino-acid variable regions, can be used to modulate α2AP activity and facilitate fibrinolysis. Using a phage display system, a library of Affimers was screened against α2AP.

Exploring a role for flow-induced aggregation assays in platform formulation optimisation for antibody-based proteins.

The development time of therapeutic monoclonal antibodies (mAbs) has been shortened by formulation platforms and the assessment of 'protein stability' using 'developability' assays. A range of assays are used to measure stability to a variety of stresses, including forces induced by hydrodynamic flow. We have previously developed a low-volume Extensional Flow Device (EFD) which subjects proteins to defined fluid flow fields in the presence of glass interfaces and used it to identify robust candidate sequences.

Computational Tools for Hydrogen-Deuterium Exchange Mass Spectrometry Data Analysis.

Hydrogen-deuterium exchange (HDX) has become a pivotal method for investigating the structural and dynamic properties of proteins. The versatility and sensitivity of mass spectrometry (MS) made the technique the ideal companion for HDX, and today HDX-MS is addressing a growing number of applications in both academic research and industrial settings. The prolific generation of experimental data has spurred the concurrent development of numerous computational tools, designed to automate parts of the workflow while employing different strategies to achieve common objectives.