發角蛋白或毛髮角蛋白(英語:Hair keratin)是一類在頭髮和指甲中發現的角蛋白。存在兩類毛髮角蛋白:
- 酸性的I型發角蛋白
- type I hair keratin 1, KRT31
- type I hair keratin 2, KRT32
- type I hair keratin 3A, KRT33A
- type I hair keratin 3B, KRT33B
- type I hair keratin 4, KRT34
- type I hair keratin 5, KRT35
- type I hair keratin 6, KRT36
- type I hair keratin 7, KRT37
- type I hair keratin 8, KRT38
- 鹼性的II型發角蛋白
- type II hair keratin 1, KRT81
- type II hair keratin 2, KRT82
- type II hair keratin 3, KRT83
- type II hair keratin 4, KRT84
- type II hair keratin 5, KRT85
- type II hair keratin 6, KRT86