恶性疟原虫海南株节结相关组氨酸富集蛋白基因的克隆及序列分析  

Cloning and sequence analysis of KAHRP gene of Plasmodium falciparum isolate FCC1/HN

作　　者：单志新[1] 余新炳[1] 徐劲[1] 吴忠道[1] 李学荣[1] 卞国武[1] 马长玲[1] 

机构地区：[1]中山大学中山医学院寄生虫学研究所,广州510089

出　　处：《热带医学杂志》2002年第1期16-20,共5页Journal of Tropical Medicine

基　　金：广东省自然科学基金 (No .980 0 89);教育部博士点基金 (No .93 186 );广东省自然科学基金团队项目资助

摘　　要：目的　克隆恶性疟原虫海南株 (FCC1/HN)节结相关组氨酸富集蛋白 (KAHRP)基因 ,并进行序列分析。方法　采用PCR技术分两段从FCC1/HN株基因组DNA中扩增出部分序列重叠的KAHRP基因片段 ,分别克隆入 pMD 18T测序载体。用双脱氧链末端终止法测定这 2个片段的序列 ,从而得到全长KAHRP基因序列。应用AnthProt、DNAstar软件辅助分析基因结构及进行同源性比较。结果　恶性疟原虫FCC1/HN株KAHRP全基因长 2 35 8个核苷酸 ,在 112至 5 6 4位核苷酸是内含子 ,全基因编码 6 34个氨基酸残基 ,其中赖氨酸含量为14 35 % ,丙氨酸含量为 9 15 % ,组氨酸含量为 7 72 % ;分子量为 6 9 37kDa。序列分析表明 ,我国恶性疟原虫FCC1/HN株与国外的 3D7、FCR3、India 1、India 2、NF17、Palo alto、PUPSP株KAHRP基因编码的氨基酸残基有 5 2个氨基酸残基替代位点 ,并存在氨基酸残基序列的增加和缺失。经多参数综合分析 ,可能有 5个潜在的抗原表位区。结论　克隆了恶性疟原虫FCC1/HN株KAHRP基因。序列测定及同源性分析表明 。Objective To clone and to analyze the structure of the sequence of the knob-associated histidine-rich protein (KAHRP)gene of Plasmodium falciparum isolate FCC1/HN. Methods Two overlapped KAHRP gene fragments were amplified by PCR from genomic DNA and cloned into pMD18-T vector by T-A cloning method. The DNA sequences of the two DNA fragments were determined by dideoxy chain termination method. The AnthProt, DNASTAR software were used to analyze the structure of KAHRP gene and homology between the KAHRP genes among different P.falciparum isolates. Results The KAHRP gene of isolate FCC1/HN was 2358 base pairs in length, with an intron located at 112～564 nt. From the sequence of the KAHRP gene of isolate FCC1/HN, it was predicted to encode for a protein about 69.37 kDa, with 634 amino acid residues, including 14.35% Lys, 9.15% Ala and 7.72% His. Isolate FCC1/HN, 3D7, FCR3, India-1, India-2, NF17, Palo-alto and PUPSP exhibited 52 amino acid substitutions and 3 amino acid addition or deletion regions in the amino acids encoded by the KAHRP gene. The results of multiple parameters analysis showed that there were 5 potent antigenic sequential epitopes in the KAHRP antigen. Conclusion The KAHRP gene of P.falciparum isolates FCC1/HN was successfully cloned. Sequence determination and structure analysis showed that the deduced amino acids of the KAHRP genes of isolate FCC1/HN and the other isolates showed a certain degree of differences.

关 键 词：恶性疟原虫 节结相关组氨酸富集蛋白 克隆 序列分析 

分 类 号：R382.31[医药卫生—医学寄生虫学]