Complexation of valinomycin (VM) with the divalent cation Ca2+ in a lipophilic solvent, acetonitrile (CH3-CN), has been studied by using circular dichroism and proton and carbon-13 nuclear magnetic resonance (1H NMR and 13C NMR). From analyses of the spectral data, it is concluded that VM forms a 2:1 (peptide-ion-peptide) sandwich complex with Ca2+, at low concentration of VM. At moderate concentrations of the salt, in addition to the sandwich complex, an equimolar (1:1) complex different from those observed for potassium and sodium is also observed. At very large concentrations of the calcium salt, the data suggested a complex with a conformation similar to that of the free VM in polar solvents. Possible conformations for the sandwich and the equimolar VM-calcium complexes are proposed.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/bi00540a006 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
The juxtamembrane sequence of small ankyrin 1 mediates the binding of its cytoplasmic domain to SERCA1 and is required for inhibitory activity.
J Biol Chem
January 2025
Department of Physiology, School of Medicine, University of Maryland Baltimore, Baltimore, MD, 21201, USA. Electronic address:
Sarcoplasmic/endoplasmic reticulum Ca-ATPase1 (SERCA1) is responsible for the clearance of cytosolic Ca in skeletal muscle. Due to its vital importance in regulating Ca homeostasis, the regulation of SERCA1 has been intensively studied. Small ankyrin 1 (sAnk1, Ank1.
View Article and Find Full Text PDFInhibition of Aβ Aggregation by Cholesterol-End-Modified PEG Vesicles and Micelles.
Pharmaceutics
December 2024
Department of Applied Chemistry, Tokyo Metropolitan University, Tokyo 192-0397, Japan.
: This study aimed to design and evaluate Chol-PEG micelles and Chol-PEG vesicles as drug delivery system (DDS) carriers and inhibitors of amyloid-β (Aβ) aggregation, a key factor in Alzheimer's disease (AD). : The physical properties of Chol-PEG assemblies were characterized using dynamic light scattering (DLS), electrophoretic light scattering (ELS), and transmission electron microscopy (TEM). Inhibitory effects on Aβ aggregation were assessed via thioflavin T (ThT) assay, circular dichroism (CD) spectroscopy, and native polyacrylamide gel electrophoresis (native-PAGE).
View Article and Find Full Text PDF()-Glucosciadopitysin, a New Biflavonoid Glycoside from the Leaves of and Osteogenic Activity of Bioflavonoids.
Plants (Basel)
January 2025
School of Pharmacy, Sungkyunkwan University, Suwon 16419, Republic of Korea.
The leaves of have been used in treating freckles and effectively reducing cough and sputum in folk medicines. Recently, investigations into the correlation between ginkgo leaves and the proliferative activity of osteogenic differentiation have been conducted. However, bioactive compounds that enhance osteogenesis or exhibit osteoporosis prevention from have not been fully identified.
View Article and Find Full Text PDFSpinorphin Molecules as Opportunities for Incorporation into Spinorphin@AuNPs Conjugate Systems for Potential Sustained Targeted Delivery to the Brain.
Pharmaceuticals (Basel)
January 2025
Institute of Neurobiology, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria.
This study explores the potential for the synthesis of peptide nanosystems comprising spinorphin molecules (with rhodamine moiety: Rh-S, Rh-S5, and Rh-S6) conjugated with nanoparticles (AuNPs), specifically peptide Rh-S@AuNPs, peptide Rh-S5@AuNPs, and peptide Rh-S6@AuNPs, alongside a comparative analysis of the biological activities of free and conjugated peptides. The examination of the microstructural characteristics of the obtained peptide systems and their physicochemical properties constitutes a key focus of this study. Zeta (ζ) potential, Fourier transformation infrared (FTIR) spectroscopy, circular dichroism (CD), scanning electron microscopy (SEM-EDS), transmission electron microscopy (TEM), and UV-Vis spectrophotometry were employed to elucidate the structure-activity correlations of the peptide@nano AuNP systems.
View Article and Find Full Text PDFSaponins Effect on Human Insulin Amyloid Aggregation.
Biomolecules
December 2024
Department of Life and Environmental Sciences, Marche Polytechnic University, I-60131 Ancona, Italy.
The misfolding and amyloid aggregation of proteins have been attracting scientific interest for a few decades, due to their link with several diseases, particularly neurodegenerative diseases. Proteins can assemble and result in insoluble aggregates that, together with intermediate oligomeric species, modify the extracellular environment. Many efforts have been and are devoted to the search for cosolvents and cosolutes able to interfere with amyloid aggregation.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!