The objective of our study was to mimic in a typical reductionist approach the molecular interactions observed at the interface between the gp130 receptor and interleukin-6 during formation of their complex. A peptide system obtained by reproducing some of the interleukin-6/gp130 molecular interactions into a two-helix bundle structure was investigated. The solution conformational features of this system were determined by CD and NMR techniques. The CD titration experiments demonstrated that the interaction between the designed peptides is specific and based on a well-defined stoichiometry. The NMR data confirmed some of the structural features of the binding mechanism as predicted by the rational design and indicated that under our conditions the recognition specificity and affinity can be explained by the formation of a two-helix bundle. Thus, the data reported herein represent a promising indication on how to develop new peptides able to interfere with formation of the interleukin-6/gp130 complex.
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http://dx.doi.org/10.1002/psc.434 | DOI Listing |
Chem Commun (Camb)
January 2024
Department of Life Science and Applied Chemistry, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya, Aichi 466-8555, Japan.
This study explores a new method for delivering therapeutic proteins into specific cells using OLE-ZIP capsules that present IgG. OLE-ZIP capsules is a spherical caspules prepared from amphihilic dimetic coiled-coil peptide, OLE-ZIP. Upon presenting cetuximab, these capsules showed preferential uptake in A431 cells and increased cytotoxicity when loaded with RNase A.
View Article and Find Full Text PDFChem Sci
April 2023
Department of Pharmacy, Ludwig-Maximilians-University Butenandstraße 5-13 81377 Munich Germany
Four helically folded aromatic oligoamide sequences containing either a chiral monomer based on 2-(2-aminophenoxy)-propionic acid, an N-terminal (1)-camphanyl group, or both, were synthesized. Spectroscopic solution investigations using H NMR and circular dichroism (CD) demonstrated that the 2-(2-aminophenoxy)-propionic acid unit biases helix handedness quantitatively in chloroform and dichloromethane. It even quantitatively overcomes an opposing effect of the camphanyl group and thus ensures reliable helix handedness control.
View Article and Find Full Text PDFJ Bacteriol
December 2022
Department of Biological Sciences, University of Notre Damegrid.131063.6, Notre Dame, Indiana, USA.
Pathogenic mycobacteria use the ESX-1 secretion system to escape the macrophage phagosome and survive infection. We demonstrated that the ESX-1 system is regulated by feedback control in Mycobacterium marinum, a nontuberculous pathogen and model for the human pathogen Mycobacterium tuberculosis. In the presence of a functional ESX-1 system, the WhiB6 transcription factor upregulates expression of ESX-1 substrate genes.
View Article and Find Full Text PDFInt J Biol Macromol
May 2022
Department of Chemistry, Chonnam National University, Gwangju 61186, Republic of Korea. Electronic address:
Type I restriction-modification enzymes are oligomeric proteins composed of methylation (M), DNA sequence-recognition (S), and restriction (R) subunits. The different bipartite DNA sequences of 2-4 consecutive bases are recognized by two discerned target recognition domains (TRDs) located at the two-helix bundle of the two conserved regions (CRs). Two M-subunits and a single S-subunit form an oligomeric protein that functions as a methyltransferase (MS MTase).
View Article and Find Full Text PDFJ Mol Biol
May 2022
Institut de Biologie Structurale (IBS), Univ. Grenoble Alpes, CEA, CNRS, 71 Avenue des Martyrs, 38000 Grenoble, France. Electronic address:
To understand the dynamic interactions between the phosphoprotein (P) and the nucleoprotein (N) within the transcription/replication complex of the Paramyxoviridae and to decipher their roles in regulating viral multiplication, we characterized the structural properties of the C-terminal X domain (P) of Nipah (NiV) and Hendra virus (HeV) P protein. In crystals, isolated NiV P adopted a two-helix dimeric conformation, which was incompetent for binding its partners, but in complex with the C-terminal intrinsically disordered tail of the N protein (N), it folded into a canonical 3H bundle conformation. In solution, SEC-MALLS, SAXS and NMR spectroscopy experiments indicated that both NiV and HeV P were larger in size than expected for compact proteins of the same molecular mass and were in conformational exchange between a compact three-helix (3H) bundle and partially unfolded conformations, where helix α is detached from the other two.
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