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.

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.

• Authors: E Theodorsson-Norheim, H Jörnvall, M Andersson, I Norheim, K Oberg, G Jacobsson
• Journal: European journal of biochemistry (Eur J Biochem) Vol. 166 Issue 3 Pg. 693-7 (Aug 03 1987) ISSN: 0014-2956 [Print] England
• PMID: 3038549 (Publication Type: Journal Article)

Chemical References

• Neuropeptides
• Peptide Fragments
• Water
• Neurokinin A

Topics

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