CXCL8 (Interleukin8) is a72 amino acid chemokine that plays an important role in immunological and inflammatory processes and is involved in Rheumatoid arthritis and cancer. [1,2] An inhibiting effect of a commercially available humanized monoclonal anti-XCL8 antibody for the CXCL8:CXCR1 interaction was observed in cell assays but the specific binding site(epitope)was still unknown. [3]

Earlier studies showed that the CXCL8 binding sites to CXCR1 are the N-Terminus,30S-Loop and N-Loop (fig.1). [3,4] The knowledge about the epitope could give insights into the mechanism and contribute to the development of new drugs. For digestion of the CXCL8 a standard method and a high-pressure (HP) method are compared. The HP method should enhance digestion times and help by the digestion of very stable proteins combined with the same enzyme specificity