ModiQuest Research has developed a sensitive Antibody Based Assay to test for Peptidyl Arginine Deiminase (PAD) activity (ABAP). The ABAP is an Enzyme Linked-Immuno-Sorbent Assay (ELISA) for the determination of PAD enzyme activity in cell and tissue lysates. Please click here to go to our online shop directly.

PAD enzymes are transcriptional co-regulators that catalyze the calcium dependent conversion of specific arginine residues present in for instance histones to citrulline.  In diseases such as multiple sclerosis and rheumatoid arthritis (RA) these PAD enzymes seem to be dysregulated. For instance in RA these enzymes become active when they exit the cell in regions of joint inflammation where they deiminate arginines in proteins such as vimentin and fibrinogen. The level of PAD activity has been correlated with RA severity. The ABAP test is also suitable for determining PAD activity of purified recombinant PAD enzymes used in various bioassays.

The MQR-ABAP test is a powerful method to rapidly screen for PAD activity. Compared to currently used assays for PAD activity determination such as the DAMO BAEE conversion test the MQR-ABAP assay is more robust, and at least 500 times more sensitive.  The ABAP kit consists of: 1) 96-well plate coated with Arginine containing peptides 2) A ModiQuest Research mouse PAD enzyme for activity calibration 3) a proprietary ModiQuest Research HRP-labelled monoclonal antibody specifically binding deiminated arginines. A detalied spec. sheet for the ABAP test can be downloaded by clicking here (PDF 192Kb).