_:b665390079 . _:b665390079 . _:b665390079 . _:b665390079 . _:b665390079 . _:b665390079 "3-carboxy-3-mercaptopropanoate (CHEBI:38707) is tautomer of 1,2-dicarboxyethanethiolate (CHEBI:38709) because 3-carboxy-3-mercaptopropanoate is deprotonated on the carboxylic acid whereas 1,2-dicarboxyethanethiolate is deprotonated on the secondary thiol." . _:b665390079 . _:b665390079 .