PROBLEM TO BE SOLVED: To provide an osteoclast differentiation control peptide that can suppress osteoclast differentiation by strongly binding to TRAF-C domain of TRAF6 and inhibiting interaction with RANK, and an agent for treating osteoclast differentiation-related disease.SOLUTION: The present invention provides an osteoclast differentiation control peptide that is a tetravalent peptide, wherein, to each of four amino groups at ends of a molecule nuclear structure formed by three lysines (Lys) bound to one another, one of peptide motifs having specific amino acid sequences is bound directly or through a spacer.SELECTED DRAWING: Figure 17COPYRIGHT: (C)2020,JPO&INPIT【課題】TRAF6のTRAF-Cドメインに強力に結合し、RANKとの相互作用を阻害することにより破骨細胞分化を抑制できる破骨細胞分化制御ペプチドと、破骨細胞分化に関連する疾患の治療薬の提供。【解決手段】破骨細胞分化制御ペプチドは、３つのリジン（Lys）が結合して形成された分子核構造の端部に位置する４つのアミノ基の各々に、特定のアミノ酸配列を有するペプチドモチーフのうちのいずれか１種が、直接又はスペーサーを介して結合している４価ペプチドの提供。【選択図】図１７
