Biotechnology Letters

, Volume 39, Issue 7, pp 1009–1018 | Cite as

Molecular and biochemical characterization of squalene synthase from Siraitia grosvenorii

  • Heling Su
  • Yongming Liu
  • Yalun Xiao
  • Yanlian Tan
  • Yunyan Gu
  • Bin Liang
  • Hongli Huang
  • Yaosheng Wu
Original Research Paper



To clone and characterize the squalene synthase from Siraitia grosvenorii (SgSQS).


The gene encoding SgSQS was cloned. SgSQS has 417 amino acid residues with an pI of 7.3. There are 32 phosphorylation sites in its sequence: S48 as well as S196 play important roles in regulation of enzyme activity. The enzyme is a monomeric protein with a cave-like active center formed by α helixes and has two transmembrane domains at its C-terminus. SgSQS mRNA expression in stem and root were about twice as much as that in leaf and peel. Full-length SgSQS with measurable catalytic activity was expressed in Escherichia coli. SgSQS activity was optimal at 37 °C and pH 7.5 respectively.


SgSQS gene was cloned, and the molecular structure and biochemical function of SgSQS were characterized.


Cloning Enzymatic properties Gene expression Sequence analysis Siraitia grosvenorii Squalene synthase 



This work was supported by the National Natural Science Foundation of China (31260069) and the Training Project of the Outstanding Higher Education Teachers of Guangxi (2014) supported by the Education Department of Guanxi Zhuang Autonomous Region, China. We thank Dr. Shanhong Ling at Monash University, Melbourne, Australia, for his help in the manuscript preparation and edition.

Supporting information

Supplementary Fig. 1—Phylogenetic tree of the squalene synthases from Siraitia grosvenorii and other terrestrial plants.

Supplementary Fig. 2—Analysis of the tissue-specific expression of the squalene synthase from Siraitia grosvenorii using qRT-PCR.

Supplementary Fig. 3—Activity assay of the recombinant squalene synthase from Siraitia grosvenorii (SgSQS) for determination of K m and V max values.

Supplementary material

10529_2017_2328_MOESM1_ESM.docx (395 kb)
Supplementary material 1 (DOCX 394 kb) Supplementary Fig. 1 Phylogenetic tree of the squalene synthases from Siraitia grosvenorii and other terrestrial plants. The tree was constructed by the neighbor-joining method using MEGA 5.0 program based on the deduced amino acid sequences of these plants. Bootstrap values of >70% are indicated at each node, and GenBank accession numbers and clone numbers are showed on the branches of the tree
10529_2017_2328_MOESM2_ESM.docx (35 kb)
Supplementary material 2 (DOCX 35 kb) Supplementary Fig. 2 Analysis of the tissue-specific expression of the squalene synthase from Siraitia grosvenorii using qRT-PCR
10529_2017_2328_MOESM3_ESM.docx (153 kb)
Supplementary material 3 (DOCX 153 kb) Supplementary Fig. 3 Activity assay of the recombinant squalene synthase from Siraitia grosvenorii (SgSQS) for determination of K m and V max values. a Michaelis–Menten plot of SgSQS activity on FPP. b Lineweaver–Burk plot of SgSQS activity on FPP. c Michaelis–Menten plot of SgSQS activity on NADPH. d Lineweaver–Burk plot of SgSQS activity on NADPH


  1. Chen W, Wang J, Qi X, Xie B (2007) The antioxidant activities of natural sweeteners, mogrosides, from fruits of Siraitia grosvenori. Int J Food Sci Nutr 58:548–556CrossRefPubMedGoogle Scholar
  2. Di R, Huang MT, Ho CT (2011) Anti-inflammatory activities of mogrosides from Momordica grosvenori in murine macrophages and a murine ear edema model. J Agric Food Chem 59:7474–7481CrossRefPubMedGoogle Scholar
  3. Ghimire GP, Thuan NH, Koirala N, Sohng JK (2016) Advances in biochemistry and microbial production of squalene and its derivatives. J Microbiol Biotechnol 26:441–451CrossRefPubMedGoogle Scholar
  4. Haralampidis K, Trojanowska M, Osbourn AE (2002) Biosynthesis of triterpenoid saponins in plants. Adv Biochem Eng Biotechnol 75:31–49PubMedGoogle Scholar
  5. Huang D, Yao Y, Zhang H, Mei Z, Wang R, Feng L, Liu B (2015) Directed optimization of a newly identified squalene synthase from Mortierella alpina based on sequence truncation and site-directed mutagenesis. J Ind Microbiol Biotechnol 42:1341–1352CrossRefPubMedGoogle Scholar
  6. Huang HX, Su HL, Shi YL, Xiao YL, Tan YL, Liang YH, Liu YM, Wu YS (2016) Gene cloning and molecular characterizations of squalene synthase from Cucumis melo. Guihaia. doi: 10.11931/guihaia.gxzw201601035 Google Scholar
  7. Jennings SM, Tsay YH, Fisch TM, Robinson GW (1991) Molecular cloning and characterization of the yeast gene for squalene synthetase. Proc Natl Acad Sci USA 88:6038–6042CrossRefPubMedPubMedCentralGoogle Scholar
  8. Jin JS, Lee JH (2012) Phytochemical and pharmacological aspects of Siraitia grosvenoriiluo han kuo. Orient Pharm Exp Med 12:233–239CrossRefGoogle Scholar
  9. Kalra S, Kumar S, Lakhanpal N, Kaur J, Singh K (2013) Characterization of Squalene synthase gene from Chlorophytum borivilianum. Mol Biotechnol 54:944–953CrossRefPubMedGoogle Scholar
  10. Lee MH, Jeong JH, Seo JW, Shin CG, Kim YS, In JG, Yang DC, Yi JS, Choi YE (2004) Enhanced triterpene and phytosterol biosynthesis in Panax ginseng overexpressing squalene synthase gene. Plant Cell Physiol 45:976–984CrossRefPubMedGoogle Scholar
  11. Li DP, Zhang HR (2000) Studies and uses of Chinese medicine Luohanguo–a special local product of Guangxi. Guihaia 20:270–276Google Scholar
  12. Liu Y, Wu YS, Hu YL (2013) The positively selected site analysis of squalene synthase for the adaptive evolution in terrestrial plants. Chin J Biochem Mol Biol 29:91–97Google Scholar
  13. Qi XY, Chen WJ, Zhang LQ, Xie BJ (2008) Mogrosides extract from Siraitia grosvenori scavenges free radicals in vitro and lowers oxidative stress, serum glucose, and lipid levels in alloxan-induced diabetic mice. Nutr Res 28:278–284CrossRefPubMedGoogle Scholar
  14. Su HL, Xiao YL, Tan YL, Liang B, Gu YY, Liu YM, Wu YS (2016) Gene cloning and molecular characterizations of squalene synthase from Sechium edule Swartz. J Anhui Agric Sci 44:142–146Google Scholar
  15. Suzuki H, Achnine L, Xu R, Matsuda SPT, Dixon RA (2002) A genomics approach to the early stages of triterpene saponin biosynthesis in Medicago truncatula. Plant J 32:1033–1048CrossRefPubMedGoogle Scholar
  16. Takasaki M, Konoshima T, Murata Y, Sugiura M, Nishino H, Tokuda H, Matsumoto K, Kasai R, Yamasaki K (2003) Anticarcinogenic activity of natural sweeteners, cucurbitane glycosides, from Momordica grosvenori. Cancer Lett 198:37–42CrossRefPubMedGoogle Scholar
  17. Tang Q, Ma X, Mo C, Wilson IW, Song C, Zhao H, Yang Y, Fu W, Qiu D (2011) An efficient approach to finding Siraitia grosvenorii triterpene biosynthetic genes by RNA-seq and digital gene expression analysis. BMC Genom. doi: 10.1186/1471-2164-12-343 Google Scholar
  18. Thompson JF, Danley DE, Mazzalupo S, Milos PM, Lira ME, Harwood HJJ (1998) Truncation of human squalene synthase yields active crystallizable protein. Arch Biochem Biophys 350:283–290CrossRefPubMedGoogle Scholar
  19. Uchida H, Yamashita H, Kajikawa M, Ohyama K, Nakayachi O, Sugiyama R, Yamato KT, Muranaka T, Fukuzawa H, Takemura M, Ohyama K (2009) Cloning and characterization of a squalene synthase gene from a petroleum plant, Euphorbia tirucalli L. Planta 229:1243–1252CrossRefPubMedGoogle Scholar
  20. Zhao CL, Cui XM, Chen YP, Liang Q (2010) Key enzymes of triterpenoid saponin biosynthesis and the induction of their activities and gene expressions in plants. Nat Prod Commun 5:1147–1158PubMedGoogle Scholar

Copyright information

© Springer Science+Business Media Dordrecht 2017

Authors and Affiliations

  1. 1.Department of Biochemistry and Molecular BiologyGuangxi Medical UniversityNanningChina
  2. 2.Key Laboratory of Medicinal Biotechnology, Guilin Medical UniversityGuilinChina

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