新疆家蚕抗菌肽(Cecropin-XJ)特性的研究

Studies on the Properties of Cecropin-XJ from Xinjiang Silkworm

探讨了新疆家蚕抗菌肽 (Cecropin -XJ)的抗菌特性。根据琼脂糖孔穴扩散法 ,检测抗菌肽的热稳定性、抑菌效价、对氨苄青霉素抗性菌的抑菌作用 ,检测抗菌肽对酸碱盐、人造胃液的耐受性及其抗菌谱。结果表明新疆家蚕抗菌肽 (Cecropin -XJ)具有很强的热稳定性、能够杀灭氨苄青霉素抗性菌、对酸碱盐、人造胃酸有一定的耐受性 ,其杀菌活力为 :1μg/ μl抗菌肽与 2 4 0 0 0单位的氨苄青霉素杀菌活力相当。新疆家蚕抗菌肽能够杀灭革兰氏阳性菌和革兰氏阴性菌 ,而对革兰氏阳性菌的抗菌活力高于革兰氏阴性菌 ,这一发现将为抗菌肽在农业、医疗卫生、畜牧业等方面的应用奠定基础 。

The purpose of this study is to investigate the properties of recombinant Cecropin-XJ isolated from Xinjing silkworm and expressed in pichia yeast. By Agar Hole Pervasion tests, this recombinant Cecropin-XJ has exhibited an extreme heat-stable characteristic and the ability to kill ampicillin-resistant S. aureus. Moreover, we have observed that the Cecropin-XJ well tolerant to extreme acidic, basic, and high salt environments as well as resistant to 24 hours digestion by artificial gastric juice. The inhibition capability to S. aureus with 1μg/μl Cecropin-XJ is equal to 24 000U ampicillin. With a broad spectrum of antibacterial activities, the Cecropin-XJ is able to inhibit the Gram-positive bacteria and Gram-negative bacteria. However, it has exhibited a better inhibition to Gram-positive bacteria than that of Gram-negative bacteria. These findings could lead it to a broad applications for agriculture, medical, domestic animal and food industry. The further investigation of the antibacterial mechanism of Cecropin-XJ is needed.