卵白蛋白源抗菌肽的分离纯化与结构鉴定

以卵白蛋白为原料,采用胃蛋白酶水解制备具有抑菌活性的蛋白肽。通过超滤和Superdex peptide 10/300凝胶色谱分离技术获得高抑菌性组分,以抗菌肽对大肠杆菌和沙门氏菌的抑菌性为试验指标,筛选最佳抑菌性组分,再进行反相高效液相色谱分离,测定分离得到的9个组分抑菌活性,发现C3组分的抑菌活性和得率最高,其中大肠杆菌及沙门氏菌抑菌圈直径分别为(19.32±1.45),(18.74±1.27)mm。最后采用高效液相色谱—电喷雾—质谱鉴定抗菌肽的结构,显示氨基酸序列为GlyLeu-Glu-Pro-Ile-Asn-Phe-Gln(GLESINFQ)。该肽经固相合成纯度为95.84%,其抑菌活性与C3组分无显著性差异(P0.05),从而证明卵白蛋白源抗菌肽发挥抑菌活性的成分主要是肽段GLESINFQ。

Isolation, purification and identification of antimicrobial peptides from ovalbumin

The antimicrobial peptides derived from ovalbumin were prepared by Pepsin hydrolysis. High antibacterial components were obtained by ultrafiltration and Superdex peptide 10/300. The antibacterial activity of antibacterial peptides against E.coli and Salmonella was used as an experimental index to screen the best antibacterial component and then conducted the reversed high-efficiency liquid phase chromatographic separation. After measuring the antibacterial activity of the 9 components, it was found that the C3 component had the highest antibacterial activity and the diameters of bacteriostasis circles were (19.32±1.45) and (18.74±1.27) mm, respectively. Then, the structure of antimicrobial peptides was identified by HPLC (electrospray ionization-massspectrometry, HPLC-ESI-MS). The results showed that the amino acid sequence was Gly-Leu-Glu-Pro-Ile-Asn-Phe-Gln (GLESINFQ). The purity of the peptide was 95.84% by solid phase synthesis, and its antibacterial activity was not significantly different with C3 component(P>0.05). The above results prove that the main component of ovalbumin antimicrobial peptide was peptide fragment GLESINFQ.