Frontiers of Chemistry in China

, Volume 5, Issue 1, pp 88–98

Purification and characterization of two major selenium-containing proteins in selenium-rich silkworm pupas

  • Qiong Liu
  • Xueying Liang
  • Decong Hu
  • Ping Chen
  • Jing Tian
  • Hong Zhang
Research Article

DOI: 10.1007/s11458-009-0109-5

Cite this article as:
Liu, Q., Liang, X., Hu, D. et al. Front. Chem. China (2010) 5: 88. doi:10.1007/s11458-009-0109-5

Abstract

Selenium (Se) is an essential trace element in vivo involved in the defense against oxidative stress. Se deficiency is associated with many human diseases. The bioactivity of Se is dose- and species-dependent. Silkworm pupa has been reported to accumulate Se mainly in proteins. Thus the characterization of major Se-containing proteins is very important in the application of Se-rich silkworm pupas in food and drugs. In this study, crude proteins were extracted from Se-rich silkworm pupas, followed by DEAE-Sepharose and Sephedex G-75 chromatography. Se content was measured after each step to determine the highest Se-containing fraction for the next step of separation. The proteins obtained were analyzed using SDS-PAGE, followed by in-gel digestion with trypsin, and were characterized by MALDI-TOF MS and ESI-MS/MS. These data showed two proteins mainly accumulated Se in the silkworm pupas. Those two proteins were proven by mass spectrometry to be arylphorin and sex-specific storage-protein 2 precursor (SP-2), respectively. Both of them belong to the storage proteins of amino acids during metamorphosis and the non-feeding pupal stage. The results suggest that Se could be enriched by storage proteins and be supplied to silkworm pupas in accompany with amino acids for the synthesis of new Se-containing proteins and peptides.

Keywords

selenium silkworm pupa mass spectrometry arylphorin sex-specific storage-protein 2 precursor (SP-2) 

Copyright information

© Higher Education Press and Springer Berlin Heidelberg 2010

Authors and Affiliations

  • Qiong Liu
    • 1
  • Xueying Liang
    • 1
  • Decong Hu
    • 2
  • Ping Chen
    • 1
    • 3
  • Jing Tian
    • 1
  • Hong Zhang
    • 4
  1. 1.College of Life SciencesShenzhen UniversityShenzhenChina
  2. 2.Technology Center of Hubei Entry-Exit Inspection and Quarantine BureauWuhanChina
  3. 3.Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchunChina
  4. 4.College of Physics Science and TechnologyShenzhen UniversityShenzhenChina

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