Xian Ding

Publications (2)5.93 Total impact

• Article: Isolation and characterization of a novel cyanophycin synthetase from a deep-sea sediment metagenomic library.

  Jikun Du, Li Li, Xian Ding, Haiyan Hu, Yongjun Lu, Shining Zhou
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  ABSTRACT: Cyanophycin is non-ribosomally synthesized protein-like copolymer. Synthesis of cyanophycin is catalyzed by cyanophycin synthetase (CphA). In this study, a novel cyanophycin synthetase CphA49 belonging to NOR5 clade of Gammaproteobacteria was identified with primer-based screening from a deep-sea sediment metagenomic library. The cphA49 gene contained an open reading frame of 2,637 bp and encoded a protein with a predicted molecular mass of 100 kDa. A recombinant CphA49 was obtained by the functional expression of cphA49 in Escherichia coli BL21 (DE3). The biochemical properties of the purified CphA49 were determined. The optimum pH and temperature of the recombinant CphA49 were 9.0 and 40 °C, respectively. The enzyme was stable at temperatures below 40 °C. The recombinant CphA49 exhibited strict primer dependency and broad substrate specificities. Cyanophycin catalyzed by CphA49 exhibited homogenous molecular mass. The amino acid composition of cyanophycin was determined and constitutes arginine, aspartic acid, and lysine.
  Applied Microbiology and Biotechnology 04/2013; · 3.42 Impact Factor
• Article: Screening for novel quorum-sensing inhibitors to interfere with the formation of Pseudomonas aeruginosa biofilm.

  Xian Ding, Bo Yin, Li Qian, Zhirui Zeng, Zeliang Yang, Huixian Li, Yongjun Lu, Shining Zhou
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  ABSTRACT: The objective of this study was to screen for novel quorum-sensing inhibitors (QSIs) from traditional Chinese medicines (TCMs) that inhibit bacterial biofilm formation. Six of 46 active components found in TCMs were identified as putative QSIs based on molecular docking studies. Of these, three compounds inhibited biofilm formation by Pseudomonas aeruginosa and Stenotrophomonas maltophilia at a concentration of 200 µM. A fourth compound (emodin) significantly inhibited biofilm formation at 20 µM and induced proteolysis of the quorum-sensing signal receptor TraR in Escherichia coli at a concentration of 3-30 mM. Emodin also increased the activity of ampicillin against P. aeruginosa. Therefore, emodin might be suitable for development into an antivirulence and antibacterial agent.
  Journal of Medical Microbiology 08/2011; 60(Pt 12):1827-34. · 2.50 Impact Factor