title: Comparison of expression, purification and characterization of a new pectate lyase from Phytophthora capsici using two different methods.
abstract: BACKGROUND
  Pectate lyases (PELs) play an important role in the infection process of plant pathogens and also have a commercial significance in industrial applications. Most of the PELs were expressed as soluble recombinant proteins, while a few recombinant proteins were insoluble. The production of a large-scale soluble recombinant PEL would allow not only a more detailed structural and functional characterization of this enzyme but also may have important applications in the food industry.
  
  
  RESULTS
  We cloned a new pectate lyase gene (Pcpel2) from Phytophthora capsici. Pcpel2 was constructed by pET system and pMAL system, and both constructs were used to express the PCPEL2 in Escherichia coli BL21 (DE3) pLysS. The expressed products were purified using affinity chromatography and gel filtration chromatography. The purity, specific activity and pathogenicity of the purified PCPEL2 expressed by the pMAL system were higher than the purified PCPEL2 expressed by the pET system. In addition, some other characteristics of the purified PCPEL2 differed from the two systems, such as crystallographic features. Purified PCPEL2 expressed by the pMAL system was crystallized by the hanging-drop vapour-diffusion method at 289 K, and initial crystals were grown.
  
  
  CONCLUSIONS
  The two different methods and comparison presented here would be highly valuable in obtaining an ideal enzyme for the downstream experiments, and supply an useful alternative to purify some insoluble recombinant proteins.
authors.affiliation: Department of Plant Pathology, Shandong Agricultural University, Tai'an, 271018, Shandong, China.
authors.forename: Huizheng
authors.initials: H
authors.lastname: Wang
authors.forename: Li
authors.initials: L
authors.lastname: Fu
authors.forename: Xiuguo
authors.initials: X
authors.lastname: Zhang
mesh_terms: D015153:Blotting, Western; D002846:Chromatography, Affinity / Q000379:methods; D002850:Chromatography, Gel / Q000379:methods; D003460:Crystallization; D005524:Food Technology / Q000379:methods; D005656:Fungal Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D010838:Phytophthora / Q000201:enzymology* / Q000235:genetics; D018515:Plant Leaves / Q000821:virology; D011133:Polysaccharide-Lyases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D013172:Spores, Fungal / Q000254:growth & development
chemical_list: D005656:Fungal Proteins; D011994:Recombinant Proteins; D011133:Polysaccharide-Lyases; C023911:pectate lyase