Beta-defensin 126 (DEFB126)

Beta-defensin 126 (DEFB126) is a highly glycosylated, secreted, cysteine-rich cationic polypeptide belonging to the beta-defensin family, which are a subgroup of antimicrobial peptides involved in the innate immune response to microorganisms[1][3][5]. DEFB126 is produced predominantly in the male reproductive tract and coats sperm, conferring a substantial negative surface charge due to O-linked glycosylation. This function facilitates sperm passage through cervical mucus and protects sperm from recognition and attack by the female immune system[2][3][5]. The protein is also involved in the binding of sperm to oviductal epithelial cells to form a reservoir until ovulation, and its removal from sperm is necessary for successful fertilization[3][5]. Variants in DEFB126 can impair fertility, and the protein also has documented antimicrobial roles and may inhibit inflammation[1][3]. No drugs targeting DEFB126 have been described, and it is not considered a therapeutic target or receptor in current clinical use[3][5].

Other names

Defensin beta 126DEFB126C20orf8DEFB26DEFB-26ESP13.2bA530N10.1Beta-defensin 26Epididymal secretory protein 13.2HBD26hBD-26epididymis secretory sperm binding proteinDefensin, beta 126Epididymal secretory protein ESP13.2