Racemic Ac-Gly-[β,δ-(13)C]Pro-OMe was synthesized, and the kinetics and thermodynamics of the isomerization of its prolyl peptide bond were determined in nine solvents by using NMR and IR spectroscopy. The free energy of activation is 1.3 kcal/mol larger in water than in aprotic solvents, and correlates with the ability of a solvent to donate a hydrogen bond but not with solvent polarity. These results are consistent with conventional pictures of amide resonance, which require transfer of charge between oxygen and nitrogen during isomerization. Similar medium effects may modulate the stability of planar peptide bonds in the active site of peptidyl-prolyl cis-trans isomerases (PPIases) and during the folding, function, or lysis of proteins.
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http://dx.doi.org/10.1021/ja00039a072 | DOI Listing |
Int J Mol Sci
December 2024
Department of Medicine, The George Washington University School of Medicine & Health Sciences, Washington, DC 20052, USA.
Neuropeptide FF (NPFF) is an endogenous octapeptide that was originally isolated from the bovine brain. It belongs to the RFamide family of peptides that has a wide range of physiological functions and pathophysiological effects. NPFF and its receptors, NPFFR1 and NPFFR2, abundantly expressed in rodent and human brains, participate in cardiovascular regulation.
View Article and Find Full Text PDFJ Clin Med
December 2024
Second Department of Internal Medicine, University of Toyama, Toyama 930-8555, Japan.
Hypoxia-inducible factor-prolyl hydroxylase (HIF-PH) inhibitors have been developed as a treatment for renal anemia. However, their therapeutic impact on patients with concomitant heart failure remains uncertain. We investigated the impact of HIF-PH inhibitors on improving renal anemia and associated clinical outcomes in patients with heart failure.
View Article and Find Full Text PDFJ Proteome Res
January 2025
Department of Clinical Epidemiology, Shengjing Hospital of China Medical University, Shenyang 110004, China.
The present study aims to summarize the current biomarker landscape in gynecological cancers (GCs) and incorporate bioinformatics analysis to highlight specific biological processes. The literature was retrieved from PubMed, Web of Science, Embase, Scopus, Ovid Medline, and Cochrane Library. The final search was conducted on December 7, 2022.
View Article and Find Full Text PDFSci Transl Med
December 2024
Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany.
Excessive deposition of fibrillar collagen in the interstitial extracellular matrix (ECM) of human lung tissue causes fibrosis, which can ultimately lead to organ failure. Despite our understanding of the molecular mechanisms underlying the disease, no cure for pulmonary fibrosis has yet been found. We screened a drug library and found that dextromethorphan (DXM), a cough expectorant, reduced the amount of excess fibrillar collagen deposited in the ECM in cultured primary human lung fibroblasts, a bleomycin mouse model, and a cultured human precision-cut lung slice model of lung fibrosis.
View Article and Find Full Text PDFPLoS Genet
December 2024
Department of Biological Sciences, University of Idaho, Moscow, Idaho, United States of America.
Protein homeostasis relies on the accurate translation and folding of newly synthesized proteins. Eukaryotic elongation factor 2 (eEF2) promotes GTP-dependent translocation of the ribosome during translation. eEF2 folding was recently shown to be dependent on Hsp90 as well as the cochaperones Hgh1, Cns1, and Cpr7.
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