Animals sense light using photosensitive proteins-rhodopsins-containing a chromophore-retinal-that intrinsically absorbs in the ultraviolet. Visible light-sensitivity depends primarily on protonation of the retinylidene Schiff base (SB), which requires a negatively-charged amino acid residue-counterion-for stabilization. Little is known about how the most common counterion among varied rhodopsins, Glu181, functions. Here, we demonstrate that in a spider visual rhodopsin, orthologue of mammal melanopsins relevant to circadian rhythms, the Glu181 counterion functions likely by forming a hydrogen-bonding network, where Ser186 is a key mediator of the Glu181-SB interaction. We also suggest that upon light activation, the Glu181-SB interaction rearranges while Ser186 changes its contribution. This is in contrast to how the counterion of vertebrate visual rhodopsins, Glu113, functions, which forms a salt bridge with the SB. Our results shed light on the molecular mechanisms of visible light-sensitivity relevant to invertebrate vision and vertebrate non-visual photoreception.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6513861 | PMC |
| http://dx.doi.org/10.1038/s42003-019-0409-3 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Dual EGFR and telomerase inhibitory potential of new triazole tethered Schiff bases endowed with apoptosis: design, synthesis, and biological assessments.
RSC Med Chem
December 2024
Department of Pharmaceutical Chemistry, College of Pharmacy, The University of Mashreq Baghdad 10023 Iraq.
Many cancers have displayed resistance to chemotherapeutic drugs over the past few decades. EGFR has emerged as a leading target for cancer therapy inhibiting tumor angiogenesis. Besides, studies strongly suggest that blocking telomerase activity could be an effective way to control the growth of certain cancer cells.
View Article and Find Full Text PDFSolvent-Driven Self-Assembly of Discrete Ni(II)-Azide Complexes: Unraveling Unusual Behavior in Mimicking Jack Bean Urease.
Inorg Chem
January 2025
Department of Chemistry, University College of Science, University of Calcutta, 92 A.P.C. Road, Kolkata 700009, India.
The well-known inhibitory strength of 3d metal Schiff base complexes against urease enzymes has long been acknowledged, but their untapped potential to act as ureolytic mimics of active metallobiosites remained unexplored. To break the new ground, we present pyrrolidine-based mononuclear Ni(II)-azide complex {[NiL(HL)(N)]·1.5(HO)} using the N,N,O donor ligand, namely ()-4-bromo-2-(((2-(pyrrolidin-1-yl)ethyl)imino)methyl)phenol.
View Article and Find Full Text PDFNew Insights into the Modifications and Bioactivities of Indole-3-Carboxaldehyde and its Derivatives as a Potential Scaffold for Drug Design: A Mini-Review.
Mini Rev Med Chem
January 2025
Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, Johor Bahru 81310, Johor, Malaysia.
Indole, a ubiquitous structural motif in bioactive compounds, has played a pivotal role in drug discovery. Among indole derivatives, indole-3-carboxaldehyde (I3A) has emerged as a particularly promising scaffold for the development of therapeutic agents. This review delves into the recent advancements in the chemical modification of I3A and its derivatives, highlighting their potential applications in various therapeutic areas.
View Article and Find Full Text PDFUnexpected stability of the iron(II) complex by an asymmetrical Schiff base from Fe(III): structure, magnetic and Mössbauer investigations.
R Soc Open Sci
January 2025
Department of Industrial Chemistry, College of Natural and Applied Sciences, Addis Ababa Science and Technology University, PO Box 16417, Addis Ababa, Ethiopia.
The asymmetric Schiff base prepared from ethylenediamine and pyridine-2-carboxaldehyde reacts with Fe(ClO)·6HO to form the Fe(II) complex [FeL](ClO) with L = ,-diethyl-'-(pyridin-2-yl)methylene)ethane-1,2-diamine, where the Fe(III) starting material has been unexpectedly reduced to Fe(II). This complex was characterized by elemental analysis, infrared spectra, single crystal and powder X-ray diffraction measurements, variable temperature DC magnetic measurement and room temperature Mössbauer spectroscopy. The asymmetric ligand L coordinates in a tridentate fashion through its pyridyl, azomethine and amino nitrogen atoms, generating a distorted octahedral geometry around the central metal ion.
View Article and Find Full Text PDFFine-Tuning the Anisotropies of Air-Stable Single-Molecule Magnets Based on Macrocycle Ligands.
Inorg Chem
January 2025
School of Chemistry and Chemical Engineering, Northwestern Polytechnical University, Xi'an 710072, P. R. China.
Air-stable single-molecule magnets (SMMs) can be obtained by confining Dy ion in a coordination environment; however, most of the current efforts were focused on modifying the rigidity of the macrocycle ligand. Herein, we attempt to assemble air-stable SMMs based on macrocycles with a replaceable coordination site. By using an in situ 1 + 1 Schiff-base reaction of dialdehyde with diamine, three air-stable SMMs have been obtained in which one of the equatorial coordination sites can be varied from -NH- (for ), -O- (for ), and -NMe- (for ).
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!