Development of Monoclonal Antibody Against Chlorinated 192tyrosine Containing ApoAI Peptide to Screen Quality of Human High Density Lipoprotein (HDL)

ApoAI, a major protein component of HDL is considered to be a key factor which contributes for HDL’s cardio- protective functions. ApoAI is sensitive to myeloperoxidase mediated oxidative modifications under chronic inflammatory conditions such as atherosclerosis. The amino acid tyrosine at position 192 of ApoAI is considered to be one of the vulnerable sites for oxidation which impairs HDL functions and its quality. The presence of oxidized ApoAI in plasma may serve as a useful indicator of CVD risks in humans, but its detection in the clinical settings requires monoclonal antibodies (mAbs) with high specificity. In this study, we have developed mAbs against chloro- tyrosine at position 192 of ApoAI. We designed a small synthetic peptide of 7 amino acids length containing modified tyrosine residue (189-LAE-3-Cl-Y-HAK-195) based on antigenicity prediction. We coupled this peptide to Keyhole Limpet Hemocyanin (KLH) for generating mAbs. Hybridoma clones, KLH-ApoAI-F2 and KLH-ApoAI-H9, were found to be highly specific to chloro-192Tyr containing peptide of ApoAI and not to either nitro-192Tyr containing or to chloro-166Tyr and nitro-166Tyr containing peptides of ApoAI. The utility of these mAbs for screening the quality of HDL as an indicator of CVD risks in humans is discussed.