粘帚霉几丁质酶GcCHI1的结构鉴定及其抑菌作用

Identification of chitinase GcCHI1 of Gliocladium catenulatum HL-1-1 and the antibacterial characters

【目的】对分离纯化自链孢粘帚霉(Gliocladium catenulatum)HL-1-1菌株的几丁质酶Gc CHI1进行化学结构鉴定,并测定该酶对几种病原真菌的抑菌机制。【方法】几丁质酶Gc CHI1化学结构鉴定采用Nano-ESI-MS/MS技术。该酶对病原真菌菌丝生长、病原菌孢子萌发和病原菌菌核萌发的抑制作用采用牛津杯法等方法。【结果】获得几丁质Gc CHI1胰蛋白酶水解肽段的肽质量指纹谱图,较好的MS/MS图谱,以及3个肽段的氨基酸序列(均<15个氨基酸),分别为LYNSNDAIEAFISR、VIGYFTQWGIYGR、LNLGIGYYGR。经Mascot数据库检索认为与来自Stenotrophomonas maltophilials 34S1的几丁质酶A具有高度的相似性。几丁质酶Gc CHI1能明显抑制立枯丝核菌、油菜菌核病菌、番茄灰霉病菌等多种植物病原真菌的菌丝生长、孢子萌发和菌核萌发。【结论】几丁质酶Gc CHI1对多种植物病原菌有抑制作用,因此几丁质酶Gc CHI1是HL-1-1菌株抑菌作用的机制之一。

[Objective] Identification the chemical structure of chitinase Gc CHI1 that isolated and purified form Gliocladium catenulatum HL-1-1 strain, and tested the antifungal effects and revealed the antifungal mechanism on several kinds of plant pathogenic fungi. [Methods] Nano-ESI-MS/MS methods and Oxford cup method. [Results] Peptide mass fingerprint atlas of trypsin hydrolysis peptide, MS/MS atlas and 3 peptide amino acid sequences（〈15 amino acids）, called LYNSNDAIEAFISR, VIGYFTQWGIYGR and LNLGIGYYGR were received. After blasted in the Mascot database, Gc CHI1 was found the highest homology similarity with chitinase A of Stenotrophomonas maltophilial strain 34S1. Another result about antifungal effects and antifungal mechanism found chitinase Gc CHI1 inhibited hyphal elongation, spore germination and sclerotium germination of such strains as Rhizoctonia solani, Sclerotinia sclerotiorum, and Botrytis cinerea et al.. [Conclusion] This paper analyzed the chemical structure of chitinase Gc CHI1. And revealed the antigungal mechanism of biocontrol fugus HL-1-1 for chitinase Gc CHI1＇s antifungal activities.