title: Cloning, structural modelling and characterization of VesT2s, a wasp venom hyaluronidase (HAase) fromVespa tropica.
abstract: BACKGROUND
  Wasp venom is a complex mixture containing proteins, enzymes and small molecules, including some of the most dangerous allergens. The greater banded wasp (Vespa tropica) is well-known for its lethal venom, whose one of the major components is a hyaluronidase (HAase). It is believed that the high protein proportion and activity of this enzyme is responsible for the venom potency.
  
  
  METHODS
  In the present study, cDNA cloning, sequencing and 3D-structure ofVespa tropicavenom HAase were described. Anti-native HAase antibody was used for neutralization assay.
  
  
  RESULTS
  Two isoforms, VesT2a and VesT2b, were classified as members of the glycosidase hydrolase 56 family with high similarity (42-97 %) to the allergen venom HAase. VesT2a gene contained 1486 nucleotide residues encoding 357 amino acids whereas the VesT2b isoform consisted of 1411 residues encoding 356 amino acids. The mature VesT2a and VesT2b are similar in mass and pI after prediction. They are 39119.73 Da/pI 8.91 and 39571.5 Da/pI 9.38, respectively. Two catalytic residues in VesT2a, Asp107 and Glu109 were substituted in VesT2b by Asn, thus impeding enzymatic activity. The 3D-structure of the VesT2s isoform consisted of a central core (α/β)7barrel and two disulfide bridges. The five putative glycosylation sites (Asn79, Asn99, Asn127, Asn187 and Asn325) of VesT2a and the three glycosylation sites (Asn1, Asn66 and Asn81) in VesT2b were predicted. An allergenic property significantly depends on the number of putativeN-glycosylation sites. The anti-native HAase serum specifically recognized to venom HAase was able to neutralize toxicity ofV. tropicavenom. The ratio of venom antiserum was 1:12.
  
  
  CONCLUSIONS
  The wasp venom allergy is known to cause life-threatening and fatal IgE-mediated anaphylactic reactions in allergic individuals. Structural analysis was a helpful tool for prediction of allergenic properties including their cross reactivity among the vespid HAase.
authors: Protein and Proteomics Research Center for Commercial and Industrial Purposes (ProCCI), Department of Biochemistry, Faculty of Science, Khon Kaen University, Khon Kaen, 40002 Thailand.
authors: Prapenpuksiri
authors: P
authors: Rungsa
authors: Department of Chemistry, Faculty of Engineering, Rajamangala University of Technology Isan, Khon Kaen Campus, Khon Kaen, Thailand.
authors: Paroonkorn
authors: P
authors: Incamnoi
authors: Chulabhorn International College of Medicine, Thammasat University (Rangsit Campus), Pathumthani, Thailand.
authors: Sophida
authors: S
authors: Sukprasert
authors: Division of Chemistry, Faculty of Science, Nakhon Phanom University, Nakhon Phanom, Thailand.
authors: Nunthawun
authors: N
authors: Uawonggul
authors: Protein and Proteomics Research Center for Commercial and Industrial Purposes (ProCCI), Department of Biochemistry, Faculty of Science, Khon Kaen University, Khon Kaen, 40002 Thailand.
authors: Sompong
authors: S
authors: Klaynongsruang
authors: Department of Clinical Chemistry, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand.
authors: Jureerut
authors: J
authors: Daduang
authors: Protein and Proteomics Research Center for Commercial and Industrial Purposes (ProCCI), Department of Biochemistry, Faculty of Science, Khon Kaen University, Khon Kaen, 40002 Thailand.
authors: Rina
authors: R
authors: Patramanon
authors: Genome Institute, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency (NSTDA), Pathumthani, Thailand.
authors: Sittiruk
authors: S
authors: Roytrakul
authors: Protein and Proteomics Research Center for Commercial and Industrial Purposes (ProCCI), Department of Biochemistry, Faculty of Science, Khon Kaen University, Khon Kaen, 40002 Thailand ; Division of Pharmacognosy and Toxicology, Faculty of Pharmaceutical Sciences, Khon Kaen University, Khon Kaen, Thailand.
authors: Sakda
authors: S
authors: Daduang
keywords: Hyaluronidase (HAase); Vespa tropica; Wasp venom