Monoclonal antibodies against human synovial phospholipase A2

Abstract Four monoclonal antibodies (HP-1, HP-2, HP-3 and HP-4) with differing reactivities were raised against human synovial fluid phospholipase A 2 . None of them bound to exocrine phospholipases A 2 , such as those from pancreas or snake venom. However, antibodies HP-1 and HP-3 showed cross-reactivity with rabbit and rat platelet secretory phospholipases A 2 , which share common enzymatic and structural features with the human synovial enzyme. Antibodies HP-1, HP-2 and HP-3 inhibited the activity of human synovial phospholipase A 2 . The antibodies were used to develop a rapid immunoaffinity column chromatographic procedure for enzyme purification. In some preparations, the recovery of total activity after immunoaffinity column chromatography was more than 100% suggesting the existence of endogenous inhibitory factors of phospholipase A 2 in human synovial fluid.