Isolation and characterization of neurokinin A, neurokinin A(3-10) and neurokinin A(4-10) from a neutral water extract of a metastatic ileal carcinoid tumour

Eur J Biochem. 1987 Aug 3;166(3):693-7. doi: 10.1111/j.1432-1033.1987.tb13567.x.

Abstract

A metastasis to the right liver lobe of an argyrophil/argentaffin midgut carcinoid tumour in a patient with the classical carcinoid syndrome was examined for the presence of tachykinins other than substance P, using a specific antiserum. The extract was initially purified using SepPak cartridges, and subsequently subjected to cation-exchange chromatography on SP Sephadex C-25 which separated the immunoreactive material into two main components (components I and II). Both were further purified by anion-exchange chromatography on DEAE-Sephadex A-25, and by reverse-phase fast protein liquid chromatography. Component II was identified as neurokinin A by its immunochemical and chromatographic properties and amino acid sequence analysis. Component I consisted of two molecular forms which were identified as neurokinin A(3-10) and neurokinin A(4-10) by amino acid sequence analysis. The tumour tissue contained only small amounts of the eledoisin-like peptide that has earlier been demonstrated in mammalian tissues. Although this component behaved like the nonmammalian peptide eledoisin on reverse-phase HPLC and on reverse-phase ion-pair chromatography, eledoisin-specific antiserum E2 indicated that eledoisin-like peptide is not identical to eledoisin. Neurokinin A in carcinoid tumours has an N-terminal heterogeneity; this multiplicity constitutes a further support for the hypothesis that carcinoid tumours produce a number of tachykinins which may be present in different relative amounts in individual patients and may contribute to the individual differences in symptomatology.

MeSH terms

  • Carcinoid Tumor / analysis*
  • Carcinoid Tumor / secondary
  • Chromatography, High Pressure Liquid
  • Chromatography, Ion Exchange
  • Humans
  • Ileal Neoplasms / analysis*
  • Liver Neoplasms / analysis
  • Liver Neoplasms / secondary
  • Neurokinin A
  • Neuropeptides / isolation & purification*
  • Peptide Fragments / isolation & purification
  • Radioimmunoassay
  • Solubility
  • Water

Substances

  • Neuropeptides
  • Peptide Fragments
  • Water
  • Neurokinin A