Peng Qu

Publications (2)4.47 Total impact

• Article: Effect of polyethylene glycols on the alkaline-induced molten globule intermediate of bovine serum albumin.

  Peng Qu, Yongxiang Wang, Guanhui Wu, Zuhong Lu, Maotian Xu
  [show abstract] [hide abstract]
  ABSTRACT: In the present study, the formation of one molten globule-like unfolding intermediate of bovine serum albumin (BSA) at pH 11.2 has been established with the help of circular dichroism (CD) spectra, fluorescence spectroscopy and 'phase diagram' approach. Additionally, we have shown the conformational changes occurring in the pH 11.2 intermediate of BSA when it was exposed to different molecular weight polyethylene glycols (PEGs) at varying concentrations. When the pH 11.2 intermediate of BSA was treated by PEG 400 there was induction of secondary and non-native tertiary contacts. In case of PEG 8000 and PEG 20,000, the loss in secondary as well as tertiary structure was observed. PEG 8000 and 20,000 altered the conformation of the pH 11.2 intermediate and resulted in its transition to another intermediate state in which the hydrophobic patches were inaccessible.
  International journal of biological macromolecules 04/2012; 51(1-2):97-104. · 2.37 Impact Factor
• Article: A label-free oligonucleotide based thioflavin-T fluorescent switch for Ag+ detection with low background emission.

  Yongxiang Wang, Fenghua Geng, Huiying Xu, Peng Qu, Xintao Zhou, Maotian Xu
  [show abstract] [hide abstract]
  ABSTRACT: A novel fluorescent Ag(+) sensor was developed based on the label-free silver (I) specific oligonucleotide (SSO) and Thioflavine T (ThT) monomer-excimer switch. C-rich SSO which contain C-C mismatched base pairs can selectively bind to Ag(+) ions and the formed duplexes which constructed by C-Ag(+)-C structure are thermally stabilized without largely altering the double helical structure. ThT give very weak fluorescent in bulk solution and/or in the presence of SSO. However ThT shows high fluorescence in the presence of SSO and Ag(+) at the same time mainly because ThT excimer, which has the high quantum yield, formed and stabilized in the minor or major groove. Based on the discovery, we developed the novel Ag(+) sensor. Under the optimum condition, the selectivity of this system for Ag(+) over other metal ions in aqueous solution is remarkably high, and Ag(+) can be quantified over the dynamic range of 30-450 nM, with a limit of detection of ~16 nM and a linear correlation coefficient of 0.995.
  Journal of Fluorescence 01/2012; 22(3):925-9. · 2.11 Impact Factor