利用噬菌体肽库筛选抗黏附的活性多肽

Screening anti-adhesion polypeptides from phage peptide library

目的 :筛选抗内皮细胞与单核细胞黏附的活性多肽。方法 :①以氧化型低密度脂蛋白 (ox LDL ,10 0mg/L)损伤的内皮细胞作为筛选的“靶”细胞 ,从XCX15肽文库 (X代表随机氨基酸 ,C为半胱氨酸 ,X15代表编码随机 15肽 )中 ,筛选能与受损内皮细胞特异性结合的多肽。②用ELISA法鉴定部分阳性克隆 ,经DNA序列测定确定其插入的氨基酸序列。③以计数法检测特异性噬菌体多肽对内皮细胞与单核细胞黏附率的影响。结果 :①从挑选鉴定的 14个克隆中 ,得到 6个阳性克隆 ,测序结果有两个克隆的外源多肽序列相同 ,4个克隆的外源多肽中含有亮氨酸 亮氨酸重复序列。②两个序列相同的克隆的噬菌体多肽 ,能明显降低内皮细胞与单核细胞的黏附率(分别降低 17.0 %和 17.6 % ,P <0 .0 1,n =4 )。结论 :从XCX15肽文库中 ,初步鉴定出

AIM: To screen the active peptides which can suppress adhesion of monocytes to endothelial cells(ECs) from a random peptide phage library. METHODS: The ECs injured by oxidized low density lipoprotein (ox-LDL) 100 mg/L was used as target cells and polypeptides specifically binding to the injured ECs were isolated from the phage-displayed peptide library. The positive clones were characterized by ELISA, and the amino acid sequences of the peptides were deduced by DNA sequencing. Cell counting was used to evaluate the adhesion rate between ECs and monocytes. RESULTS: Six positive clones specifically binding to injured EC were isolated. Four of them contained a repeated sequence of leucine-leucine. Among the four clones, two had an identical sequence, which could reduce the adhesion rate of monocytes to ECs by 17%. CONCLUSION: One peptide which can suppress adhesion of monocytes to ECs is isolated from a random peptide phage library.