THE MONOCLONAL-ANTIBODY MAC-387 RECOGNIZES 3 S100 PROTEINS IN HUMAN NEUTROPHILS

Mac 387, a murine mAb, was previously described to detect a complex fo rm of MRP-14 and MRP-8, two calcium-binding proteins of the S100 famil y, but recent experiments suggested that Mac 387 recognized only MRP-1 4. Using two-dimensional polyacrylamide gel electrophoresis and the ve ry sensitive enhanced chemiluminescence detection system, the immunore activity of Mac 387 was compared with that of a polyclonal antibody ra ised against purified MRP-8, but cross-reacting with MRP-14 and p6, a novel S100 protein. Under such conditions, Mac 387 was found to recogn ize the three S100 proteins. This result suggests that Mac 387 might r ecognize an epitope common to the proteins of the S100 family.