Cloning, expression, and purification of the virulence-associated protein D from Xylella fastidiosa

Protein Expr Purif. 2004 Oct;37(2):320-6. doi: 10.1016/j.pep.2004.07.002.

Abstract

In this study, an efficient expression system, based on the pET32Xa/LIC vector, for producing a Xylella fastidiosa virulence-associated protein D, found to have a strong similarity to Riemerella anatipestifer and Actinobacillus actinomycetencomitans VapD protein, is presented. The protein has a molecular mass of 17.637 Da and a calculated pI of 5.49. The selected XFa0052 gene was cloned in the pET32Xa/LIC vector and the plasmid was transformed into Escherichia coli BL21 (DE3) strain at 37 degrees C, with an induction time of 2 h and 1 mM IPTG concentration. The protein present in the soluble fraction was purified by immobilized metal affinity chromatography (IMAC), and had its identity determined by mass spectrometry (MALDI-TOF) and N-terminal sequencing. The purified protein was found as a single band on SDS-PAGE and its correct folding was verified by circular dichroism spectroscopy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / physiology*
  • Base Sequence
  • Biochemistry / methods*
  • Chromatography
  • Circular Dichroism
  • Cloning, Molecular
  • Electrophoresis, Polyacrylamide Gel
  • Escherichia coli / metabolism
  • Genetic Vectors
  • Isopropyl Thiogalactoside / chemistry
  • Mass Spectrometry
  • Membrane Glycoproteins / chemistry
  • Membrane Glycoproteins / physiology*
  • Molecular Sequence Data
  • Open Reading Frames
  • Plasmids / metabolism
  • Polymerase Chain Reaction
  • Protein Structure, Tertiary
  • Recombinant Fusion Proteins / chemistry
  • Sequence Homology, Nucleic Acid
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
  • Time Factors
  • Xylella / metabolism*
  • Xylella / pathogenicity*

Substances

  • Bacterial Proteins
  • Membrane Glycoproteins
  • Recombinant Fusion Proteins
  • VapD protein, Bacteria
  • Isopropyl Thiogalactoside