Yajie Zhang

Bio: Yajie Zhang is an academic researcher from Henan Normal University. The author has contributed to research in topics: Human serum albumin & Imidazole. The author has an hindex of 3, co-authored 3 publications receiving 104 citations.

Interaction of human serum albumin with novel imidazole derivatives studied by spectroscopy and molecular docking

Abstract: This study was a detailed characterization of the interaction of a series of imidazole derivatives with a model transport protein, human serum albumin (HSA). Fluorescence and time-resolved fluorescence results showed the existence of a static quenching mode for the HSA-imidazole derivative interaction. The binding constant at 296 K was in the order of 10(4) M(-1), showing high affinity between the imidazole derivatives and HSA. A site marker competition study combined with molecular docking revealed that the imidazole derivatives bound to subdomain IIA of HSA (Sudlow's site I). Furthermore, the results of synchronous, 3D, Fourier transform infrared, circular dichroism and UV-vis spectroscopy demonstrated that the secondary structure of HSA was altered in the presence of the imidazole derivatives. The specific binding distance, r, between the donor and acceptor was obtained according to fluorescence resonance energy transfer.

A highly selective “turn-on” fluorescent chemosensor based on 8-aminoquinoline for detection of Zn2+

Abstract: A new “turn-on” fluorescent probe based on 8-aminoquinoline for detection of Zn2+ was designed, synthesized and characterized. The sensor showed excellent selectivity and sensitivity with a fluorescence enhancement to Zn2+ over other cations in CH3OH–H2O solution. The detection limit for Zn2+ by HAQT reached 2.56 × 10−7 M. The binding ratio of the HAQT–Zn2+ complex was determined to be 1 : 1 according to the Job plot. The mechanism of HAQT for the recognition of Zn2+ has been investigated by FT-IR, 1H NMR and MS analyses. These advantages allowed for the application of HAQT to detect Zn2+ in real water samples.

Biophysical Study on the Interaction between Eperisone Hydrochloride and Human Serum Albumin Using Spectroscopic, Calorimetric, and Molecular Docking Analyses.

Abstract: Eperisone hydrochloride (EH) is widely used as a muscle relaxant for patients with muscular contracture, low back pain, or spasticity. Human serum albumin (HSA) is a highly soluble negatively charged, endogenous and abundant plasma protein ascribed with the ligand binding and transport properties. The current study was undertaken to explore the interaction between EH and the serum transport protein, HSA. Study of the interaction between HSA and EH was carried by UV−vis, fluorescence quenching, circular dichroism (CD), Fourier transform infrared (FTIR) spectroscopy, Forster’s resonance energy transfer, isothermal titration calorimetry and differential scanning calorimetry. Tryptophan fluorescence intensity of HSA was strongly quenched by EH. The binding constants (Kb) were obtained by fluorescence quenching, and results show that the HSA–EH interaction revealed a static mode of quenching with binding constant Kb ≈ 104 reflecting high affinity of EH for HSA. The negative ΔG° value for binding indicated that...

A simple quinolone Schiff-base containing CHEF based fluorescence ‘turn-on’ chemosensor for distinguishing Zn2+ and Hg2+ with high sensitivity, selectivity and reversibility

Abstract: A new simple 'dual' chemosensor MQA ((E)-2-methoxy-N-((quinolin-2-yl)methylene)aniline) for distinguishing Zn2+ and Hg2+ has been designed, synthesized and characterized. The sensor showed excellent selectivity and sensitivity with a fluorescence enhancement to Zn2+/Hg2+ over other commonly coexisting cations (such as Na+, Mg2+, Al3+, K+, Mn2+, Fe2+, Fe3+, Co2+, Ni2+, Cu2+, Ga3+, Cd2+, In3+ and Pb2+) in DMSO-H2O solution (1/99 v/v), which was reversible with the addition of ethylenediaminetetraacetic acid (EDTA). The detection limit for Zn2+/Hg2+ by MQA both reached the 10-8 M level. The 1 : 1 ligand-to-metal coordination patterns of the MQA-Zn2+ and MQA-Hg2+ were calculated through a Job's plot and ESI-MS spectra, and were further confirmed by X-ray crystal structures of complexes MQA-Zn2+ and MQA-Hg2+. This chemosensor can recognize similar metal ions by coherently utilizing intramolecular charge transfer (ICT) and different electronic affinities of various metal ions. DFT calculations have revealed that the energy gap between the HOMO and LUMO of MQA has decreased upon coordination with Zn(ii)/Hg(ii).

Molecular recognition of bio-active flavonoids quercetin and rutin by bovine hemoglobin: an overview of the binding mechanism, thermodynamics and structural aspects through multi-spectroscopic and molecular dynamics simulation studies.

Abstract: The binding of two bio-active flavonoids, quercetin and rutin, with bovine hemoglobin (BHb) was investigated by multi-spectroscopic and computational (molecular docking and molecular dynamics simulation) studies. The two flavonoids were found to quench the intrinsic fluorescence of BHb through a static quenching mechanism. The binding constants at 288 K were observed to be (14.023 ± 0.73) × 104 M-1 and (7.848 ± 0.20) × 104 M-1, respectively for quercetin and rutin binding with BHb. Both rutin and quercetin were observed to increase the polarity around the Trp residues of BHb as indicated by synchronous and 3D spectral studies. No significant alterations in the secondary structural components of the protein were caused during the binding of the flavonoids as studied by CD and FTIR studies. The negative molar Gibbs free energies indicated the spontaneity of the interaction processes while the binding processes were characterized by a negative enthalpy change (ΔH) and a positive entropy change (ΔS). The possibility of energy transfer from the donor (BHb) to the acceptor molecules (flavonoids) was indicated by the FRET studies. According to the fluorescence studies, the flavonoids interact near to the β2-Trp37 residue of BHb. Excellent correlations with the experimental studies were observed from the molecular docking and molecular dynamics (MD) simulation studies. Further investigations established that these flavonoids are efficient in the inhibition of glucose mediated glycation of BHb.