Enzymic and immunochemical properties of lysozyme. Accurate definition of the antigenic site around the disulphide bridge 30–115 (site 3) by `surface simulation' synthesis

摘要: Abstract 1. Previous reports from this laboratory have shown that both Lys-33 and Lys-116 are parts of an antigenic site in native lysozyme. Similar studies tyrosine derivatives indicated one or Tyr-20 Tyr-23 located very close to The site, which was around the disulphide bridge 30–115, recently unequivocally include residues Tyr-20, Arg-21, Lys-116, Asn-113, Arg-114, Phe-34 Lys-33. This confirmed by `surface-simulation' synthetic approach we developed, foregoing eight surface were directly linked via peptide bonds, with intervening spacers where appropriate, into a single peptide. does not exist lysozyme, but simulates region it. 2. In present work several surface-simulation peptides synthesized representing various region, determine minimum structural feature retains full reactivity investigate if spatially constructed has preferred direction. 3. Lys-Asn-Arg-Gly-Phe-Lys exhibited remarkable inhibitory activity towards immune reaction lysozyme accounted entirely for maximum expected protein (i.e. about one-third total reactivity). An immunoadsorbent bound antibody 4. Arg-21 part site. previously reported immunochemical effect observed on nitration due deleterious ionic exerted modified residue adjacent Lys-96, is different Thus modification impairs even though itself conformational implications finding discussed. 5. therefore comprises five Phe-34, direction (Lys-116 Lys-33), since reverse sequence immunochemically inefficient. describes line circumscribes [2.1nm C(α)–C(α) distance Lys-33] molecule.