PROBLEM TO BE SOLVED: To provide an antibody to a specific neural protein and a method for using the same.SOLUTION: According to the present invention, there is provided an isolated antibody or fragment thereof that binds to BACE1 that reduces or inhibits the activity of a BACE1 polypeptide. The antibody may bind to the active site, i.e., an exosite of BACE1. The antibody may comprise at least one hypervariable region (HVR) selected from specific amino acid sequences.SELECTED DRAWING: None【課題】特定の神経タンパク質への抗体及びその使用方法の提供。【解決手段】BACE1ポリペプチドの活性を低減又は阻害するBACE1に結合する単離された抗体又はその断片。BACE1の活性部位、即ち、エキサイトに結合する抗体。特定のアミノ酸配列から選択される一つ以上の超可変領域(HVR)を含む抗体。【選択図】なし