. "Histidine is a nonessential amino acid. L-Histidine is called a semi-essential amino acid in children because adults generally produce adequate amounts, but children may not. Histidine is a precursor of histamine, a compound released by the immune system cells during an allergic reaction."@en . . "Histidine is a nonessential amino acid. L-Histidine is called a semi-essential amino acid in children because adults generally produce adequate amounts, but children may not. Histidine is a precursor of histamine, a compound released by the immune system cells during an allergic reaction."@en . . . "In the Foldit Lua interface, the functions structure.GetAminoAcid and structure.SetAminoAcid use lowercase \"h\" for histidine. For more, see Histidine on wikipedia."@en . "In the Foldit Lua interface, the functions structure.GetAminoAcid and structure.SetAminoAcid use lowercase \"h\" for histidine. For more, see Histidine on wikipedia."@en . . "Histidine"@en . . .