98%
921
2 minutes
20
Understanding how to moderate and improve catalytic activity is critical to improving degradable polymer production. Here, di- and monozinc catalysts, coordinated by bis(imino)diphenylamido ligands, show remarkable activities and allow determination of the factors controlling performance. In most cases, the dizinc catalysts significantly out-perform the monozinc analogs. Further, for the best dizinc catalyst, the ligand conformation controls activity: the catalyst with "folded" ligand conformation shows turnover frequency (TOF) values up to 60 000 h(-1) (0.1 mol % loading, 298 K, [LA]=1 m), whilst that with a "planar" conformation is much slower, under similar conditions (TOF=30 h(-1) ). Dizinc catalysts also perform very well under immortal conditions, showing improved control, and are able to tolerate loadings as low as 0.002 mol % whilst conserving high activity (TOF=12 500 h(-1) ).
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5089563 | PMC |
http://dx.doi.org/10.1002/anie.201602930 | DOI Listing |
J Phys Chem B
September 2025
School of Science, RMIT University, Melbourne 3000, Australia.
Pentameric ligand-gated ion channels control synaptic neurotransmission via an allosteric mechanism, whereby agonist binding induces global protein conformational changes that open an ion-conducting pore. For the proton-activated bacterial () ligand-gated ion channel (GLIC), high-resolution structures are available in multiple conformational states. We used a library of atomistic molecular dynamics (MD) simulations to study conformational changes and to perform dynamic network analysis to elucidate the communication pathways underlying the gating process.
View Article and Find Full Text PDFActa Crystallogr E Crystallogr Commun
September 2025
Department of Chemistry, Chemical Biology Lab., School of Chemical and Biotechnology, SASTRA Deemed University, Thanjavur, Tamilnadu-613401, India.
In the title salt, NH ·[B(CHO)], the boron atom is chelated by two malonate ligands in a bidentate fashion, resulting in a BO tetra-hedron with both chelate rings adopting shallow boat conformations. The extended structure features five N-H⋯O and three C-H⋯O hydrogen bonds, accounting for approximately 69.9% of the total inter-molecular inter-actions.
View Article and Find Full Text PDFACS Omega
September 2025
Laboratório de Biotecnologia Farmacêutica (pbiotech), Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-902, Brazil.
The crystallographic B-factor (Bf), also known as the Debye-Waller factor (DWF) or temperature factor, relates to the mean-square displacement of the atoms (X). X may be composed of individual contributions from lattice disorder (LT), static conformational heterogeneity (H) throughout the lattice, rigid body vibration (RB), local conformational vibration (V), and zero-point atomic fluctuation (A). The Bf has been widely employed as a surrogate measure of local protein flexibility, although such relation has not been confirmed.
View Article and Find Full Text PDFBiophys J
September 2025
CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411 008, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201 002, India. Electronic address:
The glucagon-like peptide-1 receptor (GLP-1R) is a class B G protein-coupled receptor (GPCR) that plays an important role in metabolic regulation, and consequently is a target for type 2 diabetes and obesity therapeutics. Although cholesterol has been reported to be implicated in receptor activation, its interactions with the receptor during the activation cycle have not been probed. Using coarse-grained molecular dynamics simulations, we have characterized the cholesterol interactions with GLP-1R in four conformational states: the inactive, partially active, GLP-1-bound active, and exenatide-bound active conformational states.
View Article and Find Full Text PDFJ Biosci Bioeng
September 2025
Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University, Okayama 700-8530, Japan.
Blood purification using immunoadsorbent columns is a therapeutic strategy for removing pathogenic autoantibodies in autoimmune diseases. Currently available columns have limitations: Trp/Phe columns offer cost-effectiveness and sterilizability, but lack antigen specificity and have limited capacity to remove diverse pathogenic autoantibodies; whereas Protein A/peptide/anti-human IgG columns target all antibodies, regardless of pathogenicity, limiting specificity, and often require sterile production due to low stability under sterilization conditions, except for peptide ligands. Full-length autoantigen-immobilized immunoadsorbent columns have great potential to specifically adsorb targeted autoantibodies, because autoantibodies recognize diverse epitopes that vary among individuals.
View Article and Find Full Text PDF