title: DNA-binding activity in the excretory-secretory products of Trichinella pseudospiralis (Nematoda: Trichinelloidea).
abstract: A novel DNA-binding peptide of Mr approximately 30 kDa was documented for the first time in the excretory-secretory (E-S) products of the infective-stage larvae of Trichinella pseudospiralis. Larvae recovered from muscles of infected mice were maintained for 48 h in DMEM medium. E-S products of worms extracted from the medium were analysed for DNA-binding activity by the electrophoretic mobility shift assay (EMSA). Multiple DNA-protein complexes were detected. A comparison of the Mr of proteins in the complexes indicated that they could bind to the target DNA as a dimer, tetramer or multiples of tetramers. Site selection and competition analysis showed that the binding has a low specificity. A (G/C-rich)-gap-(G/T-rich)-DNA sequence pattern was extracted from a pool of degenerate PCR fragments binding to the E-S products. Results of immunoprecipitation and electrophoretic mobility supershift assay confirmed the authenticity of the DNA-binding protein as an E-S product.
authors.affiliation: Department of Zoology, The University of Hong Kong, Pokfulam, China.
authors.forename: C H
authors.initials: CH
authors.lastname: Mak
authors.forename: R C
authors.initials: RC
authors.lastname: Ko
mesh_terms: D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D001667:Binding, Competitive; D018509:DNA, Helminth / Q000737:chemistry / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D015180:Electrophoresis, Gel, Two-Dimensional; D004591:Electrophoresis, Polyacrylamide Gel; D015801:Helminth Proteins / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D051379:Mice; D008813:Mice, Inbred ICR; D008969:Molecular Sequence Data; D008970:Molecular Weight; D011067:Poly dA-dT / Q000378:metabolism; D011089:Polydeoxyribonucleotides / Q000378:metabolism; D016133:Polymerase Chain Reaction; D011233:Precipitin Tests; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D014234:Trichinella / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*
chemical_list: D018509:DNA, Helminth; D004268:DNA-Binding Proteins; D015801:Helminth Proteins; D011089:Polydeoxyribonucleotides; C031156:poly d(I-C); D011067:Poly dA-dT