MAPAG - A COMPUTER-PROGRAM TO CONSTRUCT 2-DIMENSIONAL AND 3-DIMENSIONAL ANTIGENIC MAPS

The contact area between an antibody (Ab) and the antigen (Ag) is call ed antigenic determinant or epitope. The first step in the characteriz ation of an Ag by using monoclonal antibodies (MAb) is to map the rela tive distribution of the corresponding epitopes on the Ag surface. The computer program MAPAG has been devised to automatically construct an tigenic maps. MAPAG is fed with a binary matrix of experimental data i ndicating the ability of paired MAb to bind or not simultaneously to t he Ag. The program is interactive menu-driven and allows the user an e asy data handling. MAPAG utilizes iterative processes to construct and to adjust the final map, which is graphically shown as a 2- or a 3-di mensional model. Additionally, the antigenic map obtained can be optio nally modified by the user or readjusted by the program. The suitabili ty of MAPAG was illustrated by running experimental data from literatu re and comparing antigenic maps constructed by the program with those elaborated by the investigators without the assistance of a computer. Furthermore, since some MAb could present negative allosteric effects leading to misinterpretation of data, MAPAG has been provided with an approximate reasoning module to solve such anomalous situations. Resul ts indicated that the program can be successfully employed as a simple , fast and reliable antigenic model-builder.