0 1 0 http://purl.obolibrary.org/obo/MOD_02026 S-(cysteinyl-glycyl)-L-cysteine 'S-(cysteinyl-glycyl)-L-cysteine' SubClassOf 'disulfide conjugated residue' 'S-(cysteinyl-glycyl)-L-cysteine' SubClassOf 'modified L-cysteine residue'