The effect of peptide conformational constraint on the peptide permeation across the model membranes was examined by determining the permeability of pairs of cyclic and acyclic peptides related to c[d-Pen2, d-Pen5] enkephalin (DPDPE). The peptides were cyclized by formation of an intramolecular disulfide bridge between the second and fifth residues composed of either d-penicillamine or cysteine. In each case the acyclic peptide was three to seven times more permeable than corresponding cyclic peptide. The possibility that the differences in permeability of cyclic and acyclic peptides is based on the greater conformational freedom of the acyclic peptides in the presence of membrane was examined in more detail by isothermal titration calorimetric studies of Trp6-DPDPE and its acyclic analog. The membrane binding of the acyclic peptide is a more exothermic process than binding of its cyclic Trp6-DPDPE. The transfer of acyclic peptide from water to membrane is an enthalpy driven process, whereas the transfer of the cyclic peptide is driven by entropy.
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http://dx.doi.org/10.1034/j.1399-3011.2003.00047.x | DOI Listing |
Arch Razi Inst
June 2024
Department of Sports Physiology, Faculty of Sports Sciences, Isfahan (Khorasgan) Branch, Islamic Azad University, Isfahan, Iran.
Alzheimer's is an advanced nervous disorder related to aging. The present study aimed to determine the effect of eight-week aerobic training, along with the consumption of Linalool, Cineole, and β-Bourbonene, on the prevention and improvement of Alzheimer's disease. Mice were randomly assigned to 8 groups: control group, mice induced with Alzheimer's disease treated with β-amyloid (Alzheimer group), Alzheimer's mice treated with bioactive compounds of herbal medicine (Linalool with a concentration of 25 mg/kg, Cineole with a concentration of 100 mg/kg, and β-Bourbonene with a concentration of 10 μg/ml) by gavage for 8 weeks (Alzheimer+Biocompounds group), Alzheimer's mice treated with aerobic exercise with a moderate intensity treadmill for 8 weeks (Alzheimer's+Training group), Alzheimer's mice treated with bioactive compounds of herbal medicine and aerobic exercise for 8 weeks (Alzheimer+Biocompounds+Training group), healthy mice initially treated with bioactive compounds of herbal medication (Linalool with a concentration of 25 mg/kg, Cineol with a concentration of 100 mg/kg, and β-Bourbonene with a concentration of 0.
View Article and Find Full Text PDFJ Endocrinol
December 2024
R Moffett, School of Biomedical Sciences, University of Ulster, Coleraine, United Kingdom of Great Britain and Northern Ireland.
Glucagon-like peptide-1 receptor (GLP-1R) and neuropeptide Y receptors (NPYRs) are expressed in reproductive tissues contributing to the regulation of gonadal function. This exploratory study examines the potential impact of their modulation by assessing effects of exendin-4 (Ex-4) and peptide YY (PYY) (3-36) on endocrine ovaries and adrenals, in high-fat diet (HFD) mice. Ex-4 and PYY(3-36) reduced blood glucose and energy intake, with no effects on body weight.
View Article and Find Full Text PDFJ Alzheimers Dis
December 2024
Department of Neuroscience, School of Science and Advanced Technologies in Medicine, Hamadan University of Medical Sciences, Hamadan, Iran.
Background: Alzheimer's disease (AD) as a neurodegenerative disease can cause behavioral impairments due to oxidative stress. Aging and oxidative conditions are some AD risk factors.
Objective: We assessed the influence of geraniol (GR), an acyclic monoterpene alcohol, on behavioral functions, hippocampal oxidative status, and histological alterations in AD rats induced by amyloid-β (Aβ).
J Am Chem Soc
December 2024
Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States.
Radioisotopes of fluorine (F), scandium (Sc, Sc), lutetium (Lu), and yttrium (Y, Y) have decay properties ideally suited for targeted nuclear imaging and therapy with small biologics, such as peptides and antibody fragments. However, a single-molecule strategy to introduce these radionuclides into radiopharmaceuticals under mild conditions to afford inert in vivo complexes is critically lacking. Here, we introduce HL2 and HL3, two small-cavity macrocyclic chelator structural isomers bearing a single phosphonate functional group.
View Article and Find Full Text PDFMed Mycol
November 2024
Specialized Medical Mycology Center, Postgraduate Program in Medical Microbiology, Federal University of Ceará, Fortaleza, Ceará 60430-160, Brazil.
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