植物环蛋白(cyclotides)是一类植物中富含二硫键、由28—37个氨基酸残基组成的大环蛋白,其分子中含有一个结构独特的环胱氨酸结(cyclic cystine knot,CCK)。由于其独特的结构和广泛的生物活性,如子宫收缩、溶血、细胞毒活性、抗微生物等活性,及其能耐高温、酸解和酶解的稳定结构,可作为多肽药物设计中的模板分子进行结构修饰或活性多肽的载体,而在国际上引起广泛的关注。目前从堇菜科、茜草科和葫芦科约30种植物中发现100多个植物环蛋白,研究主要集中在澳大利亚、瑞典和美国等几个研究组,近年我们也在开展相关研究。本文主要从植物环蛋白的提取、分离、检测与结构鉴定方法,结构与性质,序列的同源性及分类,化学合成与生物合成,生物活性以及应用前景等几个方面介绍植物环蛋白的研究进展。
Cyclotides are a family of plant-derived macrocyclic peptides,which are formed by 28—37 amino acid residues and contain three disulfide bonds and the unique protein structural motif termed cyclic cystine knot.For their unique structures and various bioactivities,such as uterotonic,hemolytic,cytotoxic and anti-bacterial activities,and stability to resist thermal,acidic and proteolytic degradation,cyclotides can be used as a peptidebased combinational template and carrier for drug design,and attract more attentions from scientists.Now over 100 cyclotides have been isolated from about 30 species of Violaceae,Rubiaceae and Cucurbitaceae.Most contributions on cyclotides have been achieved by the research groups in Australia,Sweden and USA.Our lab is also investigating on cyclotides.This paper introduces cyclotides'research history,methods for extraction,isolation and detection,structural determination and classification,homological analysis of sequences,synthesis and biosynthesis,bioactivity and so on.