Detection of isolated mistletoe lectin chains in plant extracts.

New test systems which allow to detect with high sensitivity the presence of isolated subunits in mistletoe extracts subunits are proposed. Interaction of monoclonal antibodies MNA5 and mouse anti-MLA (mistletoe lectin I A-chain) immune serum with panel of synthetic octapeptides linked to the surface of polyethylene pins have been analyzed. Two main immunogenic epitopes in MLA, AETHL and DGVFNNP, were found. The second sequence can be part of the MNA5 antibody epitope as shown by antigenic prediction. Possible role of the isolated A- and B-chains of mistletoe lectins in pharmacological effects of plant extracts is discussed.