THE USE OF IMMUNOCHEMICAL TECHNIQUES AND MONOCLONAL-ANTIBODIES TO STUDY THE VIRAL COAT PROTEIN-STRUCTURE OF POTATO VIRUS-A, POTATO VIRUS-Y AND BEET NECROTIC YELLOW VEIN VIRUS

The production and characterization of monoclonal antibodies (mAbs) to the potato viruses Y and A (PVY and PVA, potyviruses), and to beet necrotic yellow vein virus (BNYVV, a furovirus) are presented. These examples illustrate the value but also some pitfalls of the use of mAbs in virological research. The pitfalls are clearly shown by the studies on PVA and BNYVV. If an incorrect selection procedure was used, mAbs were selected, which reacted only with an epitope of PVA introduced during purification of the virus and which was not present on the virion in situ. Monoclonal antibodies were selected against continuous and discontinuous epitopes to BNYVV. The discontinuous epitopes were easily destroyed by harsh assay conditions. The mAbs to PVY could be used to locate distinct epitopes on the coat protein of the virus. All mAbs proved very helpful in revealing changes in viral epitopes either during purification or after transfer to various host plants.