多粘类芽孢杆菌极端嗜热多肽的纯化及性质研究

用加热法从多粘类芽孢杆菌(Paenibacillus polymyxa)LM–3菌株的发酵液中纯化得到2个极端嗜热多肽。平板拮抗实验表明,5μL纯化多肽对稻瘟病菌(Magnaporthe grisea)抑菌率达89.6%。SDS–PAGE电泳显示纯化多肽分子量介于6000～7000u之间。多肽复性后,其中之一对稻瘟病菌表现出强的拮抗活性,命名为APPLM3(Antagonism Polypeptide from Paenibacillus polymyxa LM–3);另一个则无此活性,命名为PPLM3(Polypeptide from Paenibacillus polymyxaLM–3)。APPLM3经氨基酸测序,获得了其N–末端5个氨基酸序列(H2N–ANDPR);以该序列为靶序列在NCBI上进行相似性检索,发现其可能与3个假设蛋白(或推导蛋白)相关。APPLM3为首次报道的兼具极端嗜热性和稻瘟病菌拮抗活性的小分子多肽。

Purification of the Extreme Thermophilic Polypeptides Antagonistic to Pathogens of Magnaporthe grisea and Their Characterization

Two extreme thermophilic polypeptides were isolated from fermentation liquor of strain LM-3 which belongs to Paenibacillus polymyxa. The inhibition capacity of 5 μL purified polypeptides against Magnaporthe grisea reached to 89.6% according to results on agar plates. These two polypeptides had a molecular weight between 6 000 and 7 000 u by SDS-PAGE. They exhibited extreme thermophilic characteristic and were recovered from electro-lanes for detection of inhibition activity to M. grisea respectively. One polypeptide with strong inhibition activity to M. grisea, was named APPLM3 (Antagonism Polypeptide from Paenibacillus polymyxa LM-3), and the other without such activity was named PPLM3 (Polypeptide from Paenibacillus polymyxa LM-3). N-terminal amino acid residues of APPLM3 were then sequenced and the sequence was H2N-ANDPR by which restriction similarity comparison of amino acid sequence was conducted on NCBI Website. APPLM3 polypeptide was the first one being reported, which combined the extreme thermophilic characteristic and strong antifungal activity against M. grisea.