Recent evidence for involvement of internal water molecules in the mechanism of bacteriorhodopsin is reviewed. Water O-H stretching vibration bands in the Fourier transform IR difference spectra of the L, M and N intermediates of bacteriorhodopsin were analyzed by photoreactions at cryogenic temperatures. A broad vibrational band in L was shown to be due to formation of a structure of water molecules connecting the Schiff base to the Thr46-Asp96 region. This structure disappears in the M intermediate, suggesting that it is involved in transient stabilization of the L intermediate prior to proton transfer from the Schiff base to Asp85. The interaction of the Schiff base with a water molecule is restored in the N intermediate. We propose that water is a critical mobile component of bacteriorhodopsin, forming organized structures in the transient intermediates during the photocycle and, to a large extent, determining the chemical behavior of these transient states.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1562/2006-01-16-IR-779 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Bioactive Fused Pyrazoles Inspired by the Adaptability of 5-Aminopyrazole Derivatives: Recent Review.
Molecules
January 2025
Organometallic and Organometalloid Chemistry Department, National Research Centre, Dokki, Cairo 12622, Egypt.
Heterocyclic compounds, especially those containing the pyrazole moiety, are highly significant in organic chemistry and possess remarkable and diverse biological properties. The 5-aminopyrazole derivatives are key starting materials for the synthesis of numerous bioactive compounds such as pyrazolopyridine, pyrazolopyrimidine, pyrazoloquinazoline, and pyrazolotriazine derivatives. Many compounds inspired by the 5-aminopyrazole derivatives possess a wide spectrum of biological activities and medicinal applications such as antioxidants, anticancer agents, enzyme inhibitors, antimicrobials, and anti-tuberculosis activities.
View Article and Find Full Text PDFChitosan-Based Schiff Bases (CSBs) and Their Metal Complexes: Promising Antimicrobial Agents.
Molecules
January 2025
Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, 87036 Rende, Italy.
The scientific interest in the chemical modification of chitosan to increase its solubility and application has led to its conjugation with Schiff bases, which are interesting scaffolds endowed with diverse biological properties. The resultant chitosan-based Schiff bases (CSBs) are widely studied in scientific literature due to the myriad of activities exerted, both catalytic and biological, including anticancer, anti-inflammatory, antioxidant, and especially antimicrobial ones. Antimicrobial resistance (AMR) is one of the major public health challenges of the twenty-first century because it represents a threat to the prevention and treatment of a growing number of bacterial, parasitic, viral, and fungal infections that are no longer treatable with the available drugs.
View Article and Find Full Text PDFStructural and topological analysis of thiosemicarbazone-based metal complexes: computational and experimental study of bacterial biofilm inhibition and antioxidant activity.
BMC Chem
January 2025
Chemistry Department, Faculty of Science, Alexandria University, Alexandria, Egypt.
The structural and electronic behavior of thiosemicarbazone (TSC)-based metal complexes of Mn (II), Fe (II), and Ni (II) have been investigated. The synthesized metal complexes were characterized using elemental analysis, magnetic susceptibility, molar conductivity, FTIR, and UV-Vis spectroscopy, the computational path helped with further structural investigation. The solubility test on the TSC and its complexes revealed their solubility in most organic solvents.
View Article and Find Full Text PDFSynthesis, Characterization, Anti-nematocidal, and Computational Study of Copper(II) Complex Derived from Fluoro-substituted Schiff base Ligand.
Chem Biodivers
January 2025
Al-Azhar University - Assiut Branch, Pharmacology, Assiut, Cairo, EGYPT.
Herein, Schiff base was synthesized via reaction between 2-bromo-4-(trifluoromethoxy)aniline and 2-hydroxybenzaldehyde. The ligand was reacted with Cu(II) salt to obtain complex. The compounds were characterization using various techniques.
View Article and Find Full Text PDFProgress in injectable hydrogels for hard tissue regeneration in the last decade.
J Biomater Sci Polym Ed
January 2025
Department of Biomaterials, Faculty of Science, Iran Polymer and Petrochemical Institute, Tehran, Iran.
Bone disorders have increased with increasing the human lifespan, and despite the tissue's ability to self-regeneration, in many congenital problems and hard fractures, bone grafting such as autograft, allograft, and biomaterials implantation through surgery is traditionally used. Because of the adverse effects of these methods, the emergence of injectable hydrogels without the need for surgery and causing more pain for the patient is stunning to develop a new pattern for hard tissue engineering. These materials are formed with various natural and synthetic polymers with a crosslinked network through various chemical methods such as click chemistry, Michael enhancement, Schiff's base and enzymatic reaction and physical interactions with high water absorption which can mimic the environment of cells.
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!