|Chu Fun S|
Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/17/1994
Publication Date: N/A
Citation: N/A Interpretive Summary: Fumonisins are a class of natural mold toxins commonly found in corn. Current antibody-based methods of analysis for fumonisins use a format where fumonisins in the sample compete with an enzyme labeled toxin for binding to limited antibody sites. A commercial kit based upon such methodology requires selling toxin (fumonisin) and enzyme- labeled toxin with each kit. The antibodies developed in the present research (anti-idiotype antibodies) appear to the fumonisin antibody as if they were fumonisin itself. Because of this property commercial fumonisin immunoassays that do not require the actual toxin may one day be developed, improving safety for the analyst and reducing hazardous waste.
Technical Abstract: Anti-idiotype (ID) antibodies for fumonisin B1 (FmB) were demonstrated in rabbits after immunization with purified monoclonal antibody against FmB (FmB-mAb). ELISA analyses revealed that the anti-ID (Ab2) antibodies bound specifically to FmB-mAb but not to other types of mAb or normal mouse IgG. Specific binding of FmB-mAb with Ab2 containing epitope that resembles FmB1 structure was demonstrated in an indirect competitive ELISA in which binding of mAb to the solid-phase FmB- ovalbumin (OVA) was inhibited by Ab2. Ab2 could also be used as FmB- OVA surrogate in the indirect competitive ELISA for FmB. In the FmB- OVA based-ELISA, the concentration causing 50% (ID50) inhibition of binding of mAb to the solid-phase FmB-OVA by free FmB1 and FmB2 was found and to be 0.14 microgram and 0.15 microgram/mL, respectively. In the Ab2-based ELISAs, the ID50 binding of mAb to the solid-phase Ab2 by free FmB1 and FmB2 was found to be 0.46 microgram and 0.61 microgram/mL, respectively. The efficacy of FmB-OVA-based and Ab2- based ELISA for the analysis of FmB1 in corn was examined and a good correlation was found between these two methods. Using purified Ab2 as immunogen, polyclonal anti-anti-ID (Ab3) antibodies were generated in BALB/c mice. The Ab3 was found to have similar characteristics as those of original mAb. In ELISA, the ID50 of binding of Ab3 to the solid-phase FmB-OVA by FmB1 and FmB2 was found to be 0.19 microgram and 0.26 microgram/mL, respectively.