PROBLEM TO BE SOLVED: To provide an NAT activator that has excellent NAT activating effect even at a small usage amount, and is expected to prevent or improve various symptoms such as sleep disorder and sleep latency disorder.SOLUTION: NAT (serotonin -N-acetyltransferase) activator contains a peptide which consists of an amino acid sequence shown by the following formula (1) or (2) as an active ingredient. Formula (1): Tyr-Gln-Gln-Gln-Phe-Gln-Gln-Phe-Leu-Pro-Glu-Gly-Gln-Ser-Gln-Ser-Gln-Lys (sequence number 1), Formula (2): Val-Val-Thr-Phe-Gly-Pro-Ser-Gly-Leu-Thr-Thr-Glu-Val-Lys (sequence number 2).SELECTED DRAWING: NoneCOPYRIGHT: (C)2018,JPO&INPIT【課題】少ない使用量でもＮＡＴ活性効果に優れ、睡眠障害や入眠潜時障害等の各種症状を予防又は改善することが期待できるＮＡＴ活性化剤を提供する。【解決手段】下記式（１）又は（２）で示されるアミノ酸配列からなるペプチドを有効成分として含有するＮＡＴ（セロトニン－Ｎ－アセチルトランスフェラーゼ）活性化剤である。 式（１）：Ｔｙｒ－Ｇｌｎ－Ｇｌｎ－Ｇｌｎ－Ｐｈｅ－Ｇｌｎ－Ｇｌｎ－Ｐｈｅ－Ｌｅｕ－Ｐｒｏ－Ｇｌｕ－Ｇｌｙ－Ｇｌｎ－Ｓｅｒ－Ｇｌｎ－Ｓｅｒ－Ｇｌｎ－Ｌｙｓ（配列番号１） 式（２）：Ｖａｌ－Ｖａｌ－Ｔｈｒ－Ｐｈｅ－Ｇｌｙ－Ｐｒｏ－Ｓｅｒ－Ｇｌｙ－Ｌｅｕ－Ｔｈｒ－Ｔｈｒ－Ｇｌｕ－Ｖａｌ－Ｌｙｓ（配列番号２）【選択図】なし
