 The mixing of glutamate with nucleotides inosine-5'-monophosphate (IMP) or guanosine-5'-monophosphate (GMP) enhances the taste of umami; T1R1–T1R3 responds primarily to mixtures of glutamate and nucleotides.While researches show that the synergism occurs in some animal species with other amino acids, studies of human taste receptors show that the same reaction only occur between glutamate and the selected nucleotides.Moreover, sodium in monosodium glutamate may activate glutamate to produce a stronger umami taste.