球形毛壳菌可以通过其细胞外蛋白抑制镰刀菌的生长。两种新型β-葡聚糖酶,指定Cgglu17A和Cgglu16B,从C.globosumW7的上清液中分离,并证实具有水解镰刀菌孢霉MLS-19的细胞壁的能力。Cglu17A(397个氨基酸)被归类为糖苷水解酶家族17,而Cglu16B属于家族16(284个氨基酸)。重组蛋白Cgla17A在大肠杆菌中成功表达,并通过亲和层析纯化酶。Cggla17A的最大活性出现在pH5.5和温度50°C,但Cggla16B在pH5.0和温度50°C时显示出最大活性。大部分重金属离子对这两种酶都有抑制作用,但Cggla17A和Cgla16B分别被Ba2和Mn2激活。Cggla17A表现出很高的底物特异性,几乎只催化β-1,3-糖苷键的裂解,在各种多糖中,释放葡萄糖.然而,Cglu16B对β-1,3-糖苷和β-1,3-1,4-糖苷键均显示出高催化活性。凝集素17A是一种外切葡聚糖酶,但Cglu16B是一种基于水解特性测定的内切葡聚糖酶。两种酶都显示出潜在的抗真菌活性,在病原真菌的萌发实验中观察到了协同作用。总之,Cgglau17A(exo-1,3-β-葡聚糖酶)和Cglau16B(endo-1,3(4)-β-葡聚糖酶)被证实在控制镰刀菌的过程中起关键作用,并具有潜在的工业和农业应用价值。第一次。
Chaetomium globosum can inhibit the growth of fusarium by means of their extracellular proteins. Two novel β-glucanases, designated Cgglu17A and Cgglu16B, were separated from the supernatant of C. globosum W7 and verified to have the ability to hydrolyze cell walls of Fusarium sporotrichioides MLS-19. Cgglu17A (397 amino acids) was classified as glycoside hydrolase family 17 while Cgglu16B belongs to the family16 (284 amino acids). Recombinant protein Cgglu17A was successfully expressed in Escherichia coli, and the enzymes were purified by affinity chromatography. Maximum activity of Cgglu17A appeared at the pH 5.5 and temperature 50 °C, but Cgglu16B shows the maximum activity at the pH 5.0 and temperature 50 °C. Most of heavy metal ions had inhibition effect on the two enzymes, but Cgglu17A and Cgglu16B were respectively activated by Ba2+ and Mn2+. Cgglu17A exhibited high substrate specificity, almost only catalyzing the cleavage of β-1,3-glycosidic bond, in various polysaccharose, to liberate glucose. However, Cgglu16B showed high catalytic activities to both β-1,3-glycosidic and β-1,3-1,4-glycosidic bonds. Cgglu17A was an exo-glucanase, but Cgglu16B was an endo-glucanase based on hydrolytic properties assay. Both of two enzymes showed potential antifungal activity, and the synergistic effect was observed in the germination experiment of pathogenic fungus. In conclusion, Cgglu17A (exo-1,3-β-glucanase) and Cgglu16B (endo-1,3(4)-β-glucanase) were confirmed to play a key role in the process of C. globosum controlling fusarium and have potential application value on industry and agriculture for the first time.