目的 克隆宁夏枸杞类黄酮/异黄酮生物合成途径中的关键酶查耳酮合成酶（CHS，EC2.3.1.74）。方法 以宁夏枸杞为材料，利用同源克隆和RT-PCR技术得到1条CHS基因，并对其进行生物信息学分析。结果 该家族的cDNA 片段长为1 148 bp，编码382个氨基酸，蛋白相对分子质量为4.168×10⁴，等电点为6.22。氨基酸序列和结构分析显示CHS基因家族有一个活性位点，即查耳酮和二苯乙烯合成酶活性位点。宁夏枸杞CHS（LyCHS）蛋白很可能定位在细胞质。对二级结构和三级结构进行预测，发现LyCHS蛋白中无规则卷曲126个，α螺旋和β折叠分别为166和25个，延伸链65个。系统进化分析表明，LyCHS基因与马铃薯野生种、马铃薯、番茄具有很高的同源性。该基因已在GenBank上注册，基因序列登录号为JQ964237。结论 首次克隆了LyCHS基因片段，为研究其表达特性以及功能提供了基础。

Objective To obtain cDNA of chalcone synthase (CHS, EC 2.3.1.74) involved in the flavonoid/isoflavonoid biosynthesis pathway. Methods The partial sequence of CHS in Lycium barbarum (LyCHS) was successfully cloned by RT-PCR and using a sequence homology strategy, and the bioinformation analysis was carried out. Results The cDNA fragment of CHS gene was 1 148 bp in length, which encoded a protein of 382 amino acids with the predicted relative molecular weight of 4.168 × 10⁴. The estimated isoelectric point (pI) of the putative protein is 6.22. According to the amino acid sequence and structural analysis, it showed that this protein contained one conserved active site, namely chalcone and stilbene synthases active site. Subcellular localizations of LyCHS proteins were likely in the cytoplasm. The secondary and tertiary structures of LyCHS were abundant in α-helixs (166) and random coils (126), while were less in β-turns (25) and extended strains (65). Phylogenetic analysis showed that the genes of LyCHS were closely related to CHS in Solanum pinnatisectum, S. tuberosum, and Lycopersicon esculentum. The sequences had been registered in GenBank with the accession numbers JQ964237. Conclusion The present results provide the foundation for the next study of CHS gene about its expression and function in L. barbarum.

北方民族大学校级科研项目（2010Y046）