peptide/protein antibody 2012-08-27T05:01:08Z An immunoglobulin molecule having a specific amino acid sequence that gives each antibody the ability to adhere to and interact only with the antigen that induced its synthesis and with molecules containing structures similar to that antigen. An antigen is any substance capable of inducing a specific immune response, including but not limited to toxins, bacterial proteins and viruses. XCO:0000194 experimental_condition_ontology immunoglobulin jsmith