宣威火腿中抗菌肽的分离、纯化及鉴定

Isolation, Purification and Identification of Antimicrobial Peptides in Xuanwei Ham

为探究干腌火腿中生物活性多肽的抗菌活性及其组成,选取产自中国云南省曲靖地区的宣威火腿为材料,通过缓冲液浸提的方法提取火腿中的多肽成分。以粗提多肽对单增李斯特菌和O157型大肠杆菌的生长抑制情况为指标进行抗菌性评价,同时结合离子交换色谱、尺寸排阻色谱等技术对宣威火腿粗多肽进行分离与纯化,并选取其中抑菌活性较强的组分进行氨基酸序列测定。抑菌实验发现宣威火腿粗多肽具有显著抑制单增李斯特菌和O157型大肠杆菌生长的效果;经过逐级分离纯化得到的各组分具有不同的抑菌活性。其中组分7活性最强,对大肠杆菌和李斯特菌的抑菌率分别为98%和56%。通过Nano-LC-ESI-MS/MS肽序列鉴定,最终得到抑菌活性较强的多肽序列,分别为QYYNGEEHVRFDSDVGEYR、LRNLPNLEVLDLGTNFI、FASFEAQGALANIAVDK。将鉴定得到的3条多肽化学合成后进行抑菌实验发现,合成多肽均具有较好的抑菌效果,对O157型大肠杆菌的生长抑制效果均显著高于单增李斯特菌。研究结果表明宣威火腿中含有抑菌效果的肽类成分,从而为阐释宣威火腿多肽的功能特征提供理论依据。

In order to explore the antibacterial activity and compositions of bioactive peptides generated in dry-cured ham, Xuanwei ham, which was produced at Qujing area of Yunnan China, was selected as the material to extract the crude peptides by buffer solution method. The antibacterial activity was evaluated based on growth inhibition of Listeria monocytogenes and E. coli O157. Using the ion exchange chromatography and size exclusion chromatography, crude peptides from Xuanwei ham were extracted and purified to detect the antibacterial activity and the sequences of peptides with strong antibacterial activity were further identified with LC-MC technology. The results indicated that Xuanwei ham crude peptides significantly inhibited the growth of Listeria monocytogenes and E. coli O157. Depending on the purification by ion exchange chromatography, the crude peptides were separated to 7 fractions and the 7 th fraction had better antibacterial activities with the inhibition rate of 98% and 56% on E. coli O157 and Listeria monocytogenes, respectively. The peptide sequences of the 7 th fraction were identified as QYYNGEEHVRFDSDVGEYR, LRNLPNLEVLDLGTNFI and FASFEAQGALANIAVDK by Nano-LC-ESI-MS/MS. The three identified peptides were synthesized and also exerted stable antibacterial activity, and the inhibition effect on E. coli O157 was significantly higher than that of Listeria monocytogenes. The current results indicated that antibacterial peptides were existed in Xuanwei ham, which provided a theoretical basis for explaining the functional characteristics of the peptides in Xuanwei ham.