Suárez M Belén, Sanz Luis, Chamorro M Isabel, Rey Manuel, González Francisco J, Llobell Antonio, Monte Enrique
Centro Hispano-Luso de Investigaciones Agrarias, Departamento de Microbiología y Genética, Universidad de Salamanca, Salamanca, Spain.
Fungal Genet Biol. 2005 Nov;42(11):924-34. doi: 10.1016/j.fgb.2005.08.002. Epub 2005 Oct 13.
Trichoderma mycoparasitic activity depends on the secretion of complex mixtures of hydrolytic enzymes able to degrade the host cell wall. We have analysed the extracellular proteome secreted by T. harzianum CECT 2413 in the presence of different fungal cell walls. Significant differences were detected in 2DE maps, depending on the use of specific cell walls or chitin. A combination of MALDI-TOF and liquid chromatography mass spectrometry allowed the identification of a novel aspartic protease (P6281: MW 33 and pI 4.3) highly induced by fungal cell walls. A broad EST library from T. harzianum CECT 2413 was used to obtain the full-length sequence. The protein showed 44% identity with the polyporopepsin (EC 3.4.23.29) from the basidiomycete Irpex lacteus. Lower identity percentages were found with other pepsin-like proteases from filamentous fungi (<31%) and animals (<29%). Northern blot and promoter sequence analyses support the implication of the protease P6281 in mycoparasitism.
木霉的真菌寄生活性取决于能够降解宿主细胞壁的水解酶复杂混合物的分泌。我们分析了哈茨木霉CECT 2413在不同真菌细胞壁存在下分泌的细胞外蛋白质组。在二维电泳图谱中检测到显著差异，这取决于特定细胞壁或几丁质的使用情况。基质辅助激光解吸电离飞行时间质谱（MALDI-TOF）和液相色谱质谱联用技术鉴定出一种新型天冬氨酸蛋白酶（P6281：分子量33，等电点4.3），其受真菌细胞壁高度诱导。利用哈茨木霉CECT 2413的一个广泛的表达序列标签（EST）文库获得了全长序列。该蛋白与担子菌白耙齿菌的多孔菌胃蛋白酶（EC 3.4.23.29）有44%的同一性。与丝状真菌的其他胃蛋白酶样蛋白酶（<31%）和动物的此类蛋白酶（<29%）相比，同一性百分比更低。Northern印迹和启动子序列分析支持蛋白酶P6281参与真菌寄生作用。
