passages.id: split_8_test_1200_passage
passages.type: progene_text
passages.text: Monoclonal antibodies ( mAb ) to CCR5 , 3A9 and 5C7 , were used for biopanning a nonapeptide cysteine ( C ) - constrained phage - displayed random peptide library to ascertain contact residues and define tertiary structures of possible epitopes on CCR5 .