Bioactivities and Secondary Structure of Mast Cell Degranulating (MCD) Peptide Analogs

Abstract

Buku, A., G. Maulik and W. A. Hook. Bioactivities and secondary structure of mast cell degranulating (MCD) peptide analogs. Peptides 19(1) 1–5, 1998.—Three analogs of Mast Cell Degranulating (MCD) peptide with C-terminal and one analog with N-and C-terminal deletions were synthesized and assayed for histamine-releasing activity in mast cells. Des(20–22)-MCD and des(21)-MCD markedly decreased this activity. In des(16–17,21)-MCD this activity was completely abolished. By contrast, when the C-and N-termini were truncated in des(1–2,20–22)-MCD, the full activity of MCD peptide was restored. The possibility that these analogs trigger or inhibit oxygen radicals from neutrophils was examined in a cell-free system with a chemiluminescence assay. None of the above analogs exhibited inflammatory or anti-inflammatory activity. Changes in biological activities were correlated with structural changes, as seen by circular dichroism (CD) spectroscopy.