对多种已知植物巯基蛋白酶抑制剂(cystatin)基因的氨基酸序列进行比对分析,根据其高度保守的氨基酸序列设计一对简并引物,并从茶树品种龙井43鲜叶中提取总RNA,用RT-PCR法扩增出一204bp的cDNA特异片段,然后通过3’/5’RACE的方法,分别扩增出3’端和5’端的序列,从而获得茶树巯基蛋白酶抑制剂基因的cDNA全长序列,所得序列全长627bp,编码101个氨基酸,分子量约11.062KDa。该基因在推测的氨基酸序列中含有巯基蛋白酶抑制剂家族中高度保守的、与其活性有关的QXVXG结构,且经Blast分析表明,该基因序列与其他植物巯基蛋白酶抑制剂基因的氨基酸序列同源性为54%~77%。 Based on the amino acid sequences of many known cystatin genes, a pair of degenerate primers was designed based on their highly conserved amino acid sequences. Total RNA was extracted from fresh leaves of tea tree variety Longjing43, RT-PCR method to amplify a 204bp cDNA specific fragment, and then by 3 ’/ 5’RACE method were amplified 3’ end and 5 ’end of the sequence to obtain tea tree thiol protease inhibitor cDNA length Sequence, the resulting sequence length of 627bp, encoding 101 amino acids, a molecular weight of about 11.062KDa. The deduced amino acid sequence of this gene contains QXVXG structure which is highly conserved in the family of thiol protease inhibitors and is related to its activity. According to Blast analysis, the amino acid sequence of the gene has the amino acid sequence homology with that of other plant thiol protease inhibitors 54% ~ 77%.