Allergenic Fragments of Ryegrass <i>(Lolium perenne)</i> Pollen Allergen <i>Lol </i><i>p</i> IV

Abstract

To facilitate studies on establishing the nature of structure/function relationships of allergens, ryegrass pollen allergen, Lol p IV, was cleaved into smaller fragments by cyanogen bromide (CNBr) and the resulting peptides were further digested with trypsin. The resulting peptides were then fractionated by high performance liquid chromatography (HPLC) on a C-18 reverse phase column. The allergenic activity of the HPLC fractions was evaluated in terms of their ability to inhibit the binding of ¹²⁵l-Lol p IV to serum IgE antibodies of a grass-allergic patient. Many of these fractions inhibited the binding between the native allergen and IgE antibodies in a dose-dependent manner. The inhibitions were specific, i.e., the fractions did not inhibit the binding between ¹²⁵l-Lol p I (a group-I ryegrass pollen allergen) and the IgE antibodies present in the allergic human serum. The possibility that the allergenic peptide fractions were contaminated by the native undegraded allergen, which might have accounted for the observed inhibition, was ruled out by the fact that the native allergen could not be detected by SDS-PAGE and the elution profiles of allergenically active peptides did not coincide with that of native allergen. One of the allergenic sites recognized by monoclonal antibody (Mab) 90, i.e., site A, was located in HPLC fractions 90–100 while another allergenic site B (recognized by Mab 12) appeared to be lost following the sequential digestion of Lol p IV with CNBr and trypsin.

Subtribe‐specific monoclonal antibodies to Lolium perenne

“…Most monoclonal antibodies to pollen allergens reported to date have a degree of cross-reactivity, some react to other grasses [1][2][3][4][5], and others even react to non-grasses [6][7][8][9][10][11][12].…”

Using Monoclonal Antibodies to Characterize a Sequential Epitope on the Group I Allergen of Bermuda Grass Pollen

“…In addition, other reagents such as cynogen bromide and 2-nitro-5-thiocyanobcnzoic acid had also been applied for the studies of B cell epitopes with the use o f polyclonal antibodies [19,20], Peptide chains are cleaved by cyanogen bromide at the methionine, and cleaved by 2-nitro-5-thiocyanobenzoic acid at the cysteine. In the amino acid composition of Cyn d 1, there are 3-5 methionine residues, 7 cysteine residues, and 24-31 lysine residues [6,7].…”

Overview on denominated allergens

“…with MoAb (218,221] withMoAb [211) with MoAb [237,238] with MoAb, IgE [243] T-cell epitopes yes [228,229] yes [2341 yes [234] Reombinant production yes 1195] yes [202] yes [209,212] yes [219] yes [230] yes [230,232] yes [240] trypsin inhibito (BMAI-1) [259] a-amylase / fypsin ir>hibitor (261] profilin [264] pectase lyase (266] polyalactunsnase [270]…”