Patent ID: 8603756

Claim:
A method of identifying an antigen surrogate constrained peptoid ligand that is specifically recognized by autoantibodies comprising: (1) exposing an autoantibody associated with an autoimmune disease selected from pemphigus vulgaris to a peptoid ligand library comprising constrained peptoid ligands; (2) detecting at least one constrained peptoid ligand bound to the autoantibody and (3) identifying said bound constrained peptoid ligand; wherein said peptoid ligand is bound to a support and wherein said peptoid ligand has the formula: wherein R 1 -R 5 are independently selected from the group consisting of hydrogen, alkyl, allyl, C2-C6 alkynyl, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, isopentyl, aryl, heteroaryl, furanyl, indolyl, thiophenyl, thiazolyl, imidazolyl, isoxazoyl, oxazoyl, piperonyl, pyrazoyl, pyrrolyl, pyrazinyl, pyridyl, pyrimidyl, pyrimidinyl, purinyl, cinnolinyl, benzofuranyl, benzothienyl, benzotriazolyl, benzoxazolyl, quinolone, isoxazolyl, isoquinoline cycloalkyl, alkenyl, cycloalkenyl, phenyl, pyridyl, methoxyethyl, methylbenzyl and C1-C6 alkyl; wherein each of R 1 -R 5 may optionally be substituted with a group selected from halogen (Cl, F, Br, I), —NH 2 , —OH, —OC1-C6alkyl, —SH and pharmaceutically acceptable salts thereof.