›› 2018, Vol. 38 ›› Issue (1): 36-.doi: 10.3969/j.issn.1674-8115.2018.01.007

• Original article (Basic research) • Previous Articles     Next Articles

Evaluation of anti-tuberculosis effect of Mycobacterium tuberculosis polyphosphate kinase 2 aptamer

YANG Yang, LI Dai-rong, LI You-lun, CHEN Yu-han, WAN Qiu, LIU Jing-shu   

  1. Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
  • Online:2018-01-28 Published:2018-03-09
  • Supported by:
    National Natural Science Foundation of China, 81101216;Project of Chongqing Science and Technology Commission, cstc2016shmszx130029

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Abstract: Objective · To investigate the bacteriostasis effect of Mycobacterium tuberculosis (MTB) polyphosphate kinase 2 (PPK2) aptamer on MTB
in vitro. Methods · The bioinformatics method was used to analyze the homology of MTB PPK2 and common pathogens of respiratory tract, and the
PPK2 phylogenetic tree was constructed. The binding affinity of the PPK2 aptamer to H37Rv, BCG, Mycobacterium smegmatis, Pseudomonas aeruginosa
and Acinetobacter baumannii was analyzed by enzyme-linked oligonucleotide assay (ELONA). The PPK2 aptamer was incubated for 24 h in serum
and its biological stability in serum was analyzed by agarose gel electrophoresis. The minimum inhibitory concentration (MIC) of the PPK2 aptamer to
H37Rv was determined by micro-azure method. H37Rv was inoculated with 1 μmol/L PPK2 aptamer or random sequence on Roche culture medium for
10 d and colony growth status was observed. H37Rv was co-cultured with different concentrations of PPK2 aptamer for 10 d, absorbance at 600 nm was
measured by microplate reader. The effect of PPK2 aptamer on the growth of H37Rv was observed. Results · PPK2 phylogenetic tree constructed by
bioinformatics analysis showed that PPK2 protein of H37Rv was not closely related to the common pathogens of respiratory tract, and it was relatively
close to Pseudomonas aeruginosa. The ELONA assay results showed that the PPK2 aptamer binded selectively to H37Rv. Agarose gel electrophoresis
analysis showed PPK2 aptamer in serum was at least stable for 8 h. The MIC of the PPK2 aptamer to H37Rv was 50 nmol/L. The colony growth of Roche
culture showed that PPK2 aptamer had an inhibitory effect on H37Rv growth. Growth inhibition test showed that the absorbance at 600 nm of H37Rv
showed a decreasing trend with the increase of PPK2 aptamer concentration, which indicated that PPK2 aptamer had an inhibitory effect on H37Rv growth.
Conclusion · PPK2 aptamer has good antibacterial activity against H37Rv in vitro.

Key words: polyphosphate kinase, aptamer, Mycobacterium tuberculosis, antibacterial activity