The invention discloses a polypeptide and application thereof, and belongs to the technical field of biological
medicine. The
amino acid sequence of the polypeptide is as shown in SEQ ID NO: 1. The preparation method of the polypeptide adopts a conventional chemical
solid-
phase synthesis or
recombinant expression mode. The polypeptide is applied to preparation of drugs for improving
psoriasis. The polypeptide disclosed by the invention can obviously inhibit the inflammatory reaction of
HaCaT cells under the induction of M5
in vitro, and has good anti-inflammatory activity; in-vivo experiments show that the polypeptide can effectively improve mouse
psoriasis-like symptoms induced by
imiquimod, the thickening degree of epidermal spine
layers of mice in a polypeptide treatment group is remarkably reduced, the number of T cells at
skin lesion parts is remarkably reduced, and the infiltration degree is remarkably reduced, so that the polypeptide can inhibit epidermal spine layer hypertrophy and reduce
T cell infiltration, and the mouse
psoriasis-like symptoms can be effectively improved. The histopathological characteristics of the psoriasis are improved. In addition, the polypeptide has good safety and application potential, and a new candidate molecule is provided for
clinical treatment of psoriasis and research and development of novel drugs.