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牛乳铁蛋白素(Bovine Lactoferrcin,LfcinB)是乳铁蛋白在酸性环境下经胃蛋白酶作用N端释放的一段多肽,它具有多种生物学功能。研究LfcinB广谱抗菌性及改变LfcinB氨基酸序列对其抗菌能力的影响,寻找LfcinB抗菌作用的结构位点。人工合成LfcinB,采用琼脂扩散法测定LfcinB抗菌图谱。人工合成丙氨酸取代3位半胱氨酸的LfcinB、丙氨酸取代8位色氨酸的LfcinB和去掉2个半胱氨酸的LfcinB样品,测定最小抑菌浓度,确定LfcinB抗菌活性位点。研究结果表明:LfcinB抗菌图谱广,可抑制多种革兰氏阳性菌、革兰氏阴性菌、真菌和霉菌,且对热和pH稳定,不能被多种蛋白酶失活,其中LfcinB第八位的色氨酸和分子内二硫键为其重要抗菌作用位点。
Bovine Lactoferrcin (LfcinB) is a fragment of lactoferrin released by the pepsin N-terminal in acidic environment. It has a variety of biological functions. To study the broad-spectrum antibacterial activity of LfcinB and its effect on the antibacterial ability of LfcinB, and to search for the structural site of LfcinB antibacterial activity. Artificial synthesis of LfcinB, Agar diffusion method for the determination of LfcinB antibacterial spectrum. LfcinB with alanine substituted for 3-cysteine, LfcinB with alanine replaced with 8-tryptophan, and LfcinB with 2 cysteines removed were used to determine the minimum inhibitory concentration. The antibacterial activity site of LfcinB . The results showed that: LfcinB broad antibacterial spectrum, can inhibit a variety of Gram-positive bacteria, Gram-negative bacteria, fungi and fungi, and heat and pH stability, can not be a variety of protease inactivation, including LfcinB eighth Tryptophan and intramolecular disulfide bonds are important antibacterial sites.