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Simulations of various beta-peptides have in the last years clarified several issues concerning peptide folding equilibria and interpretation of experimental data, especially from NMR and CD spectroscopy. These simulations involved different temperatures, pH-values, ionic strengths, solvents, and force-field parameters, but a variation of these factors for one beta-peptide has not yet been done. To investigate the influence of varying these factors, we analyze the helix stability of an all-beta3-icosapeptide bearing all 20 proteinogenic amino acid side chains, which is experimentally observed to fold into a 3(14)-helix in methanol but not in water. Structural aspects, such as hydrogen-bonded rings and salt bridges, are discussed and a comparison with NMR primary (NOE distance bounds and 3J-values) and secondary (NMR derived model structures) data is made. We further investigate the reasons for the 3(14)-helix stability/instability in methanol/water. Of all factors studied, the presence of counterions seems to be the one inducing most significant effects in the simulations.
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http://dx.doi.org/10.1002/bip.20601 | DOI Listing |
Org Lett
September 2025
Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry, Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, China.
The synthesis of tirzepatide relies heavily on solid phase peptide synthesis (SPPS), a process that is both costly and time-consuming. In this paper, a novel soluble liquid-phase assisted (LPPS) strategy for the efficient synthesis of tirzepatide is presented. The efficacy of the method is based on the distinct solubility properties of the soluble tag, which enables high yield synthesis while significantly reducing wastage of amino acids and solvents.
View Article and Find Full Text PDFRSC Adv
September 2025
Departament de Química, Universitat Autònoma de Barcelona Bellaterra 08193 Barcelona Spain
Mammalian ALOX15 are allosteric enzymes but the mechanism of allosteric regulation remains a matter of discussion. Octyl (-(5-(1-indol-2-yl)-2-methoxyphenyl)sulfamoyl)carbamate inhibits the linoleate oxygenase activity of ALOX15 at nanomolar concentrations, but oxygenation of arachidonic acid is hardly affected. The mechanism of substrate selective inhibition suggests inter-monomer communication within the allosteric ALOX15 dimer complex, in which the inhibitor binding to monomer A induces conformational alterations in the structure of the active site of monomer B.
View Article and Find Full Text PDFChem Sci
August 2025
Department of Chemistry, Indian Institute of Technology Bombay Powai Mumbai - 400076 India
The supramolecular organization of functional molecules at the mesoscopic level influences their material properties. Typically, planar π-conjugated (disc- or linear-shaped) molecules tend to undergo one-dimensional (1D) stacking, whereas two-dimensional (2D) organization from such building blocks is seldom observed in spite of their technological potential. Herein, we rationally achieve both 1D and 2D organizations from a single planar, π-conjugated molecular system competitive interactions.
View Article and Find Full Text PDFDalton Trans
September 2025
Department of Chemistry, Indian Institute of Technology Guwahati, Assam 781039, India.
Motivated by copper's essential role in biology and its wide range of applications in catalytic and synthetic chemistry, this work aims to understand the effect of heteroatom substitution on the overall stability and reactivity of biomimetic Cu(II)-alkylperoxo complexes. In particular, we designed a series of tetracoordinated ligand frameworks based on iso-BPMEN = (,-bis(2-pyridylmethyl)-','-dimethylethane-1,2-diamine) with varying the primary coordination sphere using different donor atoms (N, O, or S) bound to Cu(II). The copper(II) complexes bearing iso-BPMEN and their modified heteroatom-substituted ligands were synthesized and structurally characterized.
View Article and Find Full Text PDFBiosci Biotechnol Biochem
September 2025
Research Institute for Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), Kagamiyama, Higashi-Hiroshima, Hiroshima, Japan.
Lignocellulosic biomass is a carbon-neutral resource crucial to advancing a bio-based economy. The filamentous fungus Talaromyces cellulolyticus demonstrates superior biomass saccharification efficiency compared to conventional enzyme-producing fungi, making it a promising host for enzymatic biomass conversion. To enable molecular studies, we developed a robust genetic transformation system for T.
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