胸腺五肽肽库制备及其免疫活性分析

Synthesis and immunological modulation analysis of thymopentin analogue′s library

目的合成胸腺五肽D型氨基酸取代肽库,并测定对T淋巴细胞的免疫活性。方法利用组合化学技术,采用简便的茶袋法固相合成制备肽库化合物,对得到的粗肽进行分离纯化,质谱和高效液相色谱(HPLC)测定纯度,免疫活性测定采用氚标记胸腺嘧啶掺入法。结果粗肽得率平均在54%左右。通过HPLC分离得到纯肽,经质谱及HPLC分析,所制类似物相对分子质量与胸腺五肽一致,精制后的肽得率平均在36.4%左右。对T淋巴细胞增殖反应的影响作用发现,肽库中两个类似物具有明显刺激T淋巴细胞增殖的活性作用。结论D-氨基酸置换的胸腺五肽类似物对T淋巴细胞的免疫调节作用比胸腺五肽作用更强。

Purpose To synthesize a peptide library of thymopentin with D-amino acids substituted, and to determine its effect of lymphocytic proliferation. Methods Teabag method was used to synthesize the peptide library by solid phase peptide synthesis （SPPS）. Crude peptides were separated and purified. The products were characterized by ESI-MS（Electro Spray Ionization-Mass Spectrometry） and the purities were determined by HPLC.^3H-thymidin uptake values were used as indicators of T cell proliferation. Results Thirty-two peptides were synthesized. The average yields of the crude peptides and the purified peptides were about 54 % and 36%, respectively. ESI-MS results demonstrated that all peptides in the library had the same molecular weight as that in thymopentin. HPLC results determined that the purities were above 90 %. Proliferation results showed that two compounds in the peptide library could promote ConA to induce the proliferation of T lymphocyte in certain concentration about 10 μg/nd. Conclusion D-amino acids substituted peptides of thymopentin had stronger immunological activity than thymopentin.