We have studied the fluorescence red-edge-excitation effects of human serum albumin. Our results indicate that the red-edge-excitation effects of human serum albumin depend on the pH, temperature and concentration of the denaturant. The different red-edge-excitation effects are produced by a redistribution of the energy levels both in the ground and the exited states of the chromphore aroused by changes of external conditions. Studying red-edge-excitation effects of HAS, we have observed that under of acidic pH and high temperature the two denatured states of HAS have different conformations, and at pH 7.4 with increasing temperature there was a conformation transition process similar to that of acid denaturation.
Supported liquid membrane (SLM) incorporating ionic liquids (ILs) or deep eutectic solvents (DESs) offers a promising method for ion and (bio)chemical separations and CO capture. However, a molecular understanding of whether chemical reactions occur in these confined media is crucial. We report excited-state proton transfer (ESPT) reaction of a photoacid, HPTS, in various DES-based SLMs (pore size ∼280 nm) using steady-state and time-resolved fluorescence spectroscopy.
Protein Assembly Laboratory, Department of Medical Elementology and Toxicology, School of Chemical and Life Sciences, Jamia Hamdard, New Delhi 110062, India. Electronic address:
Studies on the interactions between ligands and proteins provide insights into how a possible medication alters the structures and activities of the target or carrier proteins. The natural flavonoid aglycone Chrysin (CHR) has demonstrated anti-inflammatory, antioxidant, antiapoptotic, neuroprotective, and antineoplastic effects, both in vitro and in vivo. In this work, we investigated the impact of CHR binding on the as-yet-unexplored conformation, dynamics, and unfolding mechanism of human serum albumin (HSA).
Laboratoire de Chimie Physique des Biomolécules, UCPTS, University of Namur, 61 rue de Bruxelles, 5000 Namur, Belgium; Namur Institute of Structured Matter (NISM), University of Namur, 61 rue de Bruxelles, 5000 Namur, Belgium; Namur Research Institute for Life Sciences (NARILIS), University of Namur, 61 rue de Bruxelles, 5000 Namur, Belgium. Electronic address:
Double PHD fingers 3 (DPF3) protein exists as two splicing variants, DPF3b and DPF3a, the involvement of which in human cancer and neurodegeneration is beginning to be increasingly recognised. Both isoforms have recently been identified as intrinsically disordered proteins able to undergo amyloid fibrillation. Upon their aggregation, DPF3 proteins exhibit an intrinsic fluorescence in the visible range, referred to as deep-blue autofluorescence (dbAF).
Electron transfer (ET) quenching in nonpolar media is not as well understood as in polar environments. Here, we investigate the effect of dipole-dipole interactions between the reactants using ultrafast broadband electronic spectroscopy combined with molecular dynamics simulations. We find that the quenching of the S state of two polar dyes, coumarin 152a and Nile red, by the polar ,-dimethylaniline (DMA) in cyclohexane is faster by a factor up to 3 when exciting on the red edge rather than at the maximum of their S ← S absorption band.
Glycosylation is the most prevalent protein post-translational modification, with a quarter of glycosylated proteins having enzymatic properties. Yet, the full impact of glycosylation on the protein structure-function relationship, especially in enzymes, is still limited. Here, we show that glycosylation rigidifies the important commercial enzyme horseradish peroxidase (HRP), which in turn increases its turnover and stability.
