Two antifungal thaumatin‐like proteins from barley grain

FEBS Letters

Svendsen, Ib²  Jacobsen, Susanne¹  Hejgaard, Jørn¹ 

[1] Department of Biochemistry and Nutrition, Technical University of Denmark, DK-2800 Lyngby, Denmark;Chemical Department, Carlsberg Laboratory, DK-2500 Copenhagen Valby, Denmark

关键词: Amino acid sequence;    Antifungal;    Osmotin;    Pathogenesis related;    Thaumatin;    Hordeum vulgare;    PR;    pathogenesis-related;    PAGE;    polyacrylamide gel electrophoresis;    SDS;    sodium dodecyl sulfate;    TL;    thaumatin-like;   

DOI  :  10.1016/0014-5793(91)81119-S

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Antifungal activity has been associated with 2 immunochemically distinct proteins, protein R and S (M _r ∼23 kDa; pI 9-10), which were isolated in pure form from barley grain. The proteins are homologous with thaumatin- and pathogenesis-related proteins of the PR5 family. The proteins inhibit growth of i.a. Trichoderma viride and Candida albicans in microtiter plate assays and act synergistically with barley grain chitinase C. Like maize zeamatin, protein R and S but not chitinase C retarded fungal growth in synergism with nikkomycin Z, a nucleoside-peptide inhibitor of fungal chitin synthesis. Although no inhibition of α-amylases or serine proteases could be associated with protein R or S the results indicate that the homologous maize grain bifunctional inhibitor of insect α-amylase and trypsin is very similar to or identical with maize zeamatin, which was proposed to have permeabilizing activity towards fungal membranes. Thus, in addition to the intensely sweet properties of thaumatin, multiple unrelated defense functions against insect and fungal pests can now be associated with the family of thaumatin-homologous proteins.

【 授权许可】

Unknown