Parasin I, an antimicrobial peptide derived from histone H2A in the catfish, Parasilurus asotus

FEBS Letters

Kim, Mi Sun²  Park, In Yup¹  Kim, Sun Chang¹  Park, Chan Bae¹ 

[1] Department of Biological Sciences, Korea Advanced Institute of Science and Technology, 373-1, Yusong-gu, Kusong-dong, Taejon 305-701, South Korea;Korea Institute of Energy Research, Biomass Team, Taejon 305-343, South Korea

关键词: Antimicrobial peptide;    Histone H2A;    Epidermal injury;    Catfish;    Parasilurus asotus;   

DOI  :  10.1016/S0014-5793(98)01238-1

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

In response to epidermal injury, Parasilurus asotus, a catfish, secreted a strong antimicrobial peptide into the epithelial mucosal layer. The molecular mass of the antimicrobial peptide, named parasin I, was 2000.4 Da, as determined by matrix-associated laser desorption ionization mass spectrometry. The complete amino acid sequence of parasin I, which was determined by automated Edman degradation, was Lys-Gly-Arg-Gly-Lys-Gln-Gly-Gly-Lys-Val-Arg-Ala-Lys-Ala-Lys-Thr-Arg-Ser-Ser. Eighteen of the 19 residues in parasin I were identical to the N-terminal of buforin I, a 39-residue antimicrobial peptide derived from the N-terminal of toad histone H2A [Kim et al. (1996) Biochem. Biophys. Res. Commun. 229, 381–387], which implies that parasin I was cleaved off from the N-terminal of catfish histone H2A. Parasin I showed strong antimicrobial activity, about 12–100 times more potent than magainin 2, against a wide spectrum of microorganisms, without any hemolytic activity. Circular dichroism spectra of parasin I indicated a structural content of 11% α-helix, 33% β-sheet, and 56% random coils. The β-sheet axial projection diagram of parasin I showed an amphipathic structure. Our results indicate that the catfish may produce parasin I from its histone H2A by a specific protease upon injury to protect against invasion by microorganisms.

【 授权许可】

Unknown