rLj-RGD3全RGD缺失基因重组突变体—rLj-112分子克隆及其广谱抑真菌活性

Molecular Cloning and Antimicrobial Activity of Recombinant Lj-112,a Full RGD Deletion Mutant of Lj-RGD3 Protein

Lj-112是日本七鳃鳗RGD毒素蛋白野生型Lj-RGD3的RGD全缺失基因突变体,其一级结构具有富组氨酸的特点.富组氨酸糖蛋白具有抑菌功能.为了研究Lj-112是否具有抑菌作用,使用基因合成和原核表达的方法,获得了纯化重组蛋白r Lj-112,将其对不同菌种进行抑菌试验.结果表明,以野生型r Lj-RGD3、RGD模体与组氨酸全缺失突变体r Lj-26为对照,r Lj-112有较广谱的抑菌活性,其中对白念球菌的最低抑菌浓度(MIC)为7μmol/L,对稻瘟病菌的MIC值为7.5μmol/L,对毛癣菌和禾谷病菌的MIC值分别为11.9μmol/L和29.9μmol/L.可见,r Lj-112能作为抗真菌药物候选,为提高农作物的生产质量和减轻人类感染疾病的用药压力奠定了基础.

Lj-RGD3 is a RGD toxin protein from the buccal gland of Lampetra japonica. Lj-112 is a mutant of Lj-RGD3,which was deleted with all the three RGD motifs and reserved all of histidine sequence of Lj-RGD3. Lj-112 has a histidine-rich primary structure. Histidine-rich glycoprotein（ HRG）had antibacterial function,so we want to study whetherLj-112 also has the same antibacterial function.rLj-112 protein was obtained with gene cloning and prokaryotic expression system. The bacteriostatic experiment results showed that rLj-112 has broad-spectrum antimicrobial activity. The wild type rLjRGD3 and the mutant rLj-26 which lacks all three RGD motifs and histidine residues have not the same function. rLj-112 minimal inhibitory concentrations（ MIC） was 7 μmol / L against Candida albicans,7. 5μmol /L against Pyricularia oryzae,11. 9 μmol /L,29. 9 μmol /L against Trichophyton and Fusarium graminearum Schw. Further,rLj-112 qualify as prototypes of antimicrobial drugs that might be used to improve crop production and reduce the pressure of human disease medication laid the foundation.