Hejgaard J, Jacobsen S, Bjørn S E, Kragh K M
Department of Biochemistry and Nutrition, Technical University of Denmark, Lyngby.
FEBS Lett. 1992 Aug 3;307(3):389-92. doi: 10.1016/0014-5793(92)80720-2.
Antifungal activity in vitro has been associated with barley leaf and grain proteins which are homologous with pathogenesis related proteins of type 4 (PR-4) from tobacco and tomato and with C terminal domains of potato win and Hevea hevein precursor proteins. One protein (pI approximately 9.3, M(r) approximately 13.7 kDa) from barley grain and two very similar proteins from leaves infected with Erysiphe graminis were isolated by chitin affinity chromatography, but none of the proteins showed chitinase activity in vitro. The leaf proteins were increased several fold in response to either Erysiphe infection or NiCl2 infiltration and accumulated extracellularly. The three barley proteins were found to inhibit growth of Trichoderma harzianum in microtiter plate assays using approximately 10 micrograms/ml concentrations and in lower concentrations in a synergistic way when mixed either with barley chitinase C (a PR-3 type protein) or with barley protein R (a PR-5 type protein). Structurally similar proteins were detected in wheat, rye and oats grain extracts.
体外抗真菌活性与大麦叶片和籽粒蛋白有关，这些蛋白与烟草和番茄中4型病程相关蛋白（PR - 4）以及马铃薯win蛋白和橡胶树hevein前体蛋白的C末端结构域同源。通过几丁质亲和层析从大麦籽粒中分离出一种蛋白（pI约为9.3，M(r)约为13.7 kDa），并从感染禾白粉菌的叶片中分离出两种非常相似的蛋白，但这些蛋白在体外均未显示几丁质酶活性。叶片蛋白在禾白粉菌感染或氯化镍浸润后增加了几倍，并在细胞外积累。在微量滴定板试验中，发现这三种大麦蛋白在浓度约为10微克/毫升时能抑制哈茨木霉的生长，当与大麦几丁质酶C（一种PR - 3型蛋白）或大麦蛋白R（一种PR - 5型蛋白）混合时，在较低浓度下具有协同抑制作用。在小麦、黑麦和燕麦籽粒提取物中检测到结构相似的蛋白。
