Abstract: On the basis of crystal structure and the interaction with DNA of Netropsin, three 10 residues SPXX motif peptides were designed and synthesized. These structures are similiar to Netropsin's. The secondary structures of these peptides have been studied by circular dichroism spectra, which satisfy the criteria of β-turn consistent with those obtained by Chou & Fasman prediction method. Circular dichroismof DNA of calf thymus with diffrent quantities of these peptides revealthat they can bind to DNA. These peptides have antibacterial and antitumoractivities.

Key words: Netropsin, Chou & Fasman prediction, circular dichroism, β-turn, antibacterial and antitumor activities, peptides

摘要： 根据纺锤霉素（Netropsin）的晶体结构及与DNA作用方式，我们设计合成了3个含SPXX序列的十肽，它们在空间构象上与纺锤霉素类似。应用Chou＆Fasman蛋白质二级结构预测方法，推测3个肽应具有β-turn结构。3个肽的CD谱也证实了这一点。通过测定小牛胸腺DNA及加入不同量肽后的CD谱，表明3个肽可与DNA结合。实验证明3个肽具有抑菌抗肿瘤活性。这为以后设计选择性识别并结合DNA的多肽类药物提供了依据。

关键词: 纺锤霉素, Chou＆Fasman预测, CD谱, β-turn结构, 抑菌抗肿瘤活性, 肽