The isolation, characterization and cloning of a globin-like, host-protective antigen from the excretory-secretory products of Trichostrongylus colubriformis
| Autor: | Theo A.A. Dopheide, M. J. Frenkel, Colin W. Ward, Barry M. Wagland |
|---|---|
| Rok vydání: | 1992 |
| Předmět: |
Trichostrongylus
Sequence analysis Guinea Pigs Molecular Sequence Data Biology Molecular cloning Polymerase Chain Reaction Protein sequencing Complementary DNA Animals Humans Amino Acid Sequence Globin Cloning Molecular Molecular Biology chemistry.chemical_classification Base Sequence cDNA library Nucleic acid sequence DNA Blotting Northern Molecular biology Globins Amino acid Biochemistry chemistry Antigens Helminth Parasitology Sequence Alignment |
| Zdroj: | Molecular and Biochemical Parasitology. 50:27-36 |
| ISSN: | 0166-6851 |
| Popis: | An 18-kDa component from the excretory-secretory (ES) products of adults of Trichostrongylus colubriformis was isolated and characterized, and was shown to induce 60-84% protection of guinea pigs from challenge infection following a single intraperitoneal injection. Amino-terminal sequence analysis of gel-purified protein enabled oligonucleotides to be synthesized and used to screen a lambda gt10 cDNA library made from young adult worm mRNA, and to synthesize full-length clones from cDNA using the polymerase chain reaction (PCR). The full-length clones coded for a 20-kDa precursor protein of 173 amino acids which had a strongly hydrophobic leader sequence of 15 residues. The mature protein sequence of 158 amino acid residues was rich in charged amino acids (32%), including 8 oppositely charged pairs of amino acids. The protein sequence contained no half-cystine residues and no potential N-glycosylation sites. Unlike 2 other fully characterized ES components which are expressed only in the parasitic stages, mRNA coding for the 20-kDa component was present in both the parasitic and free-living stages of T. colubriformis. The parasite protein had approximately 20% identity with globins from human and from the larvae of the insect Chironomus thummi thummi. The homology included the invariant distal histidine and phenylalanine, and a number of other residues highly conserved in globins. |
| Databáze: | OpenAIRE |
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