The temperature-dependent behavior of a solvated oligopeptide, GVG(VPGVG), is investigated. Spectroscopic measurements, thermodynamic measurements, and molecular dynamics simulations find that this elastinlike octapeptide behaves as a two-state system that undergoes an "inverse temperature" folding transition and reentrant unfolding close to the boiling point of water. A molecular picture of these processes is presented, emphasizing changes in the dynamics of hydrogen bonding at the protein/water interface and peptide backbone librational entropy.
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http://dx.doi.org/10.1103/PhysRevLett.92.148101 | DOI Listing |
Nat Commun
January 2025
Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, Punjab, India.
Single-point mutations are pivotal in molecular zoology, shaping functions and influencing genetic diversity and evolution. Here we study three such genetic variants of a mechano-responsive protein, cadherin-23, that uphold the structural integrity of the protein, but showcase distinct genotypes and phenotypes. The variants exhibit subtle differences in transient intra-domain interactions, which in turn affect the anti-correlated motions among the constituent β-strands.
View Article and Find Full Text PDFBiophys J
January 2025
Department of Chemistry, University of Alabama at Birmingham, Birmingham, Alabama. Electronic address:
The Hsp100 family of protein disaggregases play important roles in maintaining protein homeostasis in cells. E. coli ClpB is an Hsp100 protein that solubilizes protein aggregates.
View Article and Find Full Text PDFActa Crystallogr C Struct Chem
February 2025
Departamento de Química Inorgánica, Analítica y Química Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Intendente Güiraldes 2160, Piso 3, Ciudad Universitaria, C1428EGA Buenos Aires, Argentina.
In this study, we present a new N-derivative of L-phenylalanine with 2-naphthaldehyde (PN), obtained by the Schiff base formation procedure and its subsequent reduction. This compound was crystallized as a zwitterion {2-[(naphthalen-2-ylmethyl)azaniumyl]-3-phenylpropanoate, CHNO}, as an anion in a sodium salt (catena-poly[[diaquasodium(I)-di-μ-aqua] 2-[(naphthalen-2-ylmethyl)amino]-3-phenylpropanoate monohydrate], {[Na(HO)](CHNO)·HO}), as a cation in a chloride salt [(1-carboxy-2-phenylethyl)(naphthalen-2-ylmethyl)azanium chloride acetic acid monosolvate, CHNO·Cl·CHCOOH], and additionally acting as a ligand in the pentacoordinated zinc compound aquabis{2-[(naphthalen-2-ylmethyl)amino]-3-phenylpropanoato-κO}zinc(II), [Zn(CHNO)(HO)] or [Zn(PN)(HO)], denoted (PN-Zn), with the amino acid derivative in its carboxylate form.
View Article and Find Full Text PDFTzu Chi Med J
August 2024
Department of Pediatrics, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei, Taiwan.
Endoplasmic reticulum (ER) is a crucial organelle associated with cellular homeostasis. Accumulation of improperly folded proteins results in ER stress, accompanied by the reaction involving triggering unfolded protein response (UPR). The UPR is mediated through ER membrane-associated sensors, such as protein kinase-like ER kinase (PERK), inositol-requiring transmembrane kinase/endoribonuclease 1α, and activating transcription factor 6 (ATF6).
View Article and Find Full Text PDFNat Cell Biol
January 2025
Institute of Biochemistry and Molecular Biology, Faculty of Medicine, University of Bonn, Bonn, Germany.
Mitochondria have to import a large number of precursor proteins from the cytosol. Chaperones keep these proteins in a largely unfolded state and guide them to the mitochondrial import sites. Premature folding, mitochondrial stress and import defects can cause clogging of import sites and accumulation of non-imported precursors, representing a critical burden for cellular proteostasis.
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