Agglomeration: when folded proteins clump together

Compartmentation of multiple metabolic enzymes and their preparation in vitro and in cellulo

Compartmentalization of multiple enzymes in cellulo and in vitro is a means of controlling the cascade reaction of metabolic enzymes. The compartmentation of enzymes through liquid-liquid phase separation may facilitate the reversible control of biocatalytic cascade reactions, thereby reducing the transcriptional and translational burden. This has attracted attention as a potential application in bioproduction. Recent research has demonstrated the existence and regulatory mechanisms of various enzyme compartments within cells. Mounting evidence suggests that enzyme compartmentation allows in vitro and in vivo regulation of cellular metabolism. However, the comprehensive regulatory mechanisms of enzyme condensates in cells and ideal organization of cellular systems remain unknown. This review provides an overview of the recent progress in multiple enzyme compartmentation in cells and summarizes strategies to reconstruct multiple enzyme assemblies in vitro and in cellulo. By examining parallel examples, we have evaluated the consensus and future perspectives of enzyme condensation.

Exploring biochemical considerations for diffusive alpha radiation therapy (DaRT) models

Diffusing alpha-emitting Radiation Therapy (DaRT) is a cancer treatment currently undergoing clinical trials. DaRT utilizes localized 224-Radium (224Ra) seeds to deliver high linear energy transfer (LET) alpha radiation. Its main advantage over other alpha radiation treatments is that the diffusion of 224Ra decay chain products allows for a more spatially distributed dose. In silico models are used to simulate the physical dynamics of DaRT and the diffusion of DaRT progeny radionuclides into cancer tissue. These models mostly rely on physical principles, often neglecting biochemical interactions with the tumor microenvironment (TME), which affect DaRT dosimetry in human cancer tissue. Here, we address this gap by reviewing how the daughter isotope 212-Lead (212Pb) interacts with chemically heterogeneous TMEs during DaRT treatments. 212Pb is given special attention due to its high physiological activity and long half-life compared to other DaRT radionuclides. By investigating Pb-binding molecules in the TME and their molecular dynamics, we aim to highlight key biochemical processes to be considered by computational models. We identify several species with prevalent roles in cancer tissue as possible binding partners with 212Pb. These species include Glutathione (GSH), Metallothioneins (MTs), Calmodulin (CaM), and Human Serum Albumin (HSA). GSH, MTs, CaM, and HSA were selected based on their known ability to bind to Pb and their concentration in cancer tissue and were examined for their variability in diverse TMEs. Ultimately, this article seeks to guide future research by providing a basic framework of molecular species important for the accurate simulation of DaRT within the TME.

Biophysical Reviews: A goodbye to 2023

This Editorial for the IUPAB Biophysical Reviews journal (2023 volume 15 issue 6) first provides an overview of the contents of this "Regular Issue featuring an Issue Focus on the Computational Biophysics of Atomic Force Microscopy" before going on to highlight some of the notable work published in the journal throughout 2023. Highlights of the current Issue include the contributed review article by Antonio Benedetto, winner of the 2023 Michèle Auger Award for Young Scientists' Independent Research, the latest installment of the "Biophysical Reviews Top 5 Series" authored by Angela Dulhunty, and an Issue Focus on the topic of computational aspects of atomic force microscopy generated from an IUPAB-sponsored workshop held in 2022.