Leah R, Tommerup H, Svendsen I, Mundy J
Carlsberg Research Laboratory, Copenhagen, Denmark.
J Biol Chem. 1991 Jan 25;266(3):1564-73.
We have purified three proteins from barley (Hordeum vulgare L.) seeds which synergistically inhibit the growth of fungi measured in a microtiter well assay. The proteins are a 26-kDa chitinase, a 30-kDa ribosome-inactivating protein, and a 32-kDa (1-3)-beta-glucanase. Full-length cDNAs encoding them were isolated and sequenced to determine the complete primary structures of the proteins. Northern hybridizations with the cDNAs as probes showed that the corresponding mRNAs accumulate differentially during seed development and germination. Chitinase mRNA accumulates to high levels in aleurone cells during late seed development and early germination, while high levels of mRNA encoding the ribosome-inactivating protein accumulate only in the starchy endosperm during late seed development. The glucanase mRNA accumulates to low levels during seed development and to higher levels in aleurone and seedling tissues during germination. Southern hybridizations showed that the three proteins are encoded by small families of three to eight genes. Their biological roles and potential use in genetic engineering studies are discussed.
我们从大麦（Hordeum vulgare L.）种子中纯化出了三种蛋白质，在微孔板检测中，它们能协同抑制真菌生长。这三种蛋白质分别是一种26 kDa的几丁质酶、一种30 kDa的核糖体失活蛋白以及一种32 kDa的（1-3）-β-葡聚糖酶。我们分离并测序了编码这些蛋白质的全长cDNA，以确定蛋白质的完整一级结构。以这些cDNA为探针进行的Northern杂交显示，相应的mRNA在种子发育和萌发过程中差异积累。几丁质酶mRNA在种子发育后期和早期萌发时在糊粉层细胞中积累到高水平，而编码核糖体失活蛋白的mRNA仅在种子发育后期的淀粉胚乳中积累到高水平。葡聚糖酶mRNA在种子发育过程中积累到低水平，在萌发时在糊粉层和幼苗组织中积累到较高水平。Southern杂交表明，这三种蛋白质由三到八个基因的小家族编码。文中讨论了它们的生物学作用以及在基因工程研究中的潜在用途。
