PROBLEM TO BE SOLVED: To provide antibodies recognizing a BDNF prodomain or a BDNF propeptide specifically.SOLUTION: An antibody or an antigen binding fragment thereof has the following characteristics: (1) recognizing the 19th-128th BDNF prodomain of proBDNF represented by SEQ ID NO: 1 and the 19th-128th of BDNF propeptide of proBDNF but recognizing no maturation BDNF; (2) not recognizing the following region A of a BDNF prodomain but specifically recognizing the following region B and/or the following region C, (the wavy underlined parts are the common parts of the region A and the region B; the underlined parts are the common parts of the region B and the region C.)SELECTED DRAWING: None【課題】BDNFプロドメインもしくはBDNFプロペプチドを特異的に認識する抗体を提供する。【解決手段】下記の特徴を有する抗体又はその抗原結合性フラグメント(1)配列番号1で示されるproBDNFの19番目~128番目のBDNFプロドメイン及びproBDNFの19番目~128番目のBDNFプロペプチドを認識するが、成熟BDNFを認識しない(2)BDNFプロドメインの領域Aは認識しないが、領域B及び/又は領域Cを特異的に認識する、 【化1】(下波線部は領域Aと領域Bの共通部分であり、下線部は領域Bと領域Cの共通部分である。)【選択図】なし