CAJ | 학술논문

采用生物信息学分析方法对 GenBank 中来源于茶树、可可、山茶等植物咖啡碱合成酶的氨基酸序列进行比对分析，就等电点、亚细胞定位、信号肽、跨膜螺旋、保守性功能结构域及基序、二级结构与三级结构等重要参数进行预测与分析。结果表明，植物咖啡碱合成酶主要定位于胞质和胞核中，含有磷酸化、酰基化和糖基化修饰位点，基于基因序列与保守结构域可被分成3种类型，其中 I 型与 II 型酶蛋白均属全α型水溶性酶蛋白，III 型酶蛋白除二级结构富含无规卷曲构件，还极有可能存在信号肽序列，但3类酶蛋白均无跨膜螺旋，三级结构预测显示，I 型、II 型酶蛋白极为相似，由α螺旋和横向β-折叠片层组成，III 型则α螺旋位于横向两端，中间由纵向β-折叠片层连接。
채용생물신식학분석방법대 GenBank 중래원우다수、가가、산다등식물가배감합성매적안기산서렬진행비대분석，취등전점、아세포정위、신호태、과막라선、보수성공능결구역급기서、이급결구여삼급결구등중요삼수진행예측여분석。결과표명，식물가배감합성매주요정위우포질화포핵중，함유린산화、선기화화당기화수식위점，기우기인서렬여보수결구역가피분성3충류형，기중 I 형여 II 형매단백균속전α형수용성매단백，III 형매단백제이급결구부함무규권곡구건，환겁유가능존재신호태서렬，단3류매단백균무과막라선，삼급결구예측현시，I 형、II 형매단백겁위상사，유α라선화횡향β-절첩편층조성，III 형칙α라선위우횡향량단，중간유종향β-절첩편층련접。
The amino acid sequences of caffeine synthase from Camellia sinensis ,Theobroma cacao ,Camellia japonica and other plants which were registered in GenBank,were analyzed and predicted by bioinformatic tools in subsequent aspects, including the isoelectric point, subcellular localization, signal peptide, transmembrane topologieal structure,conserved functional domain,motif,secondary structure and tertiary structure of protein. Results showed that the caffeine synthase of plants which were located in cytoplasm and nuclei, and had phosphorylation,acylation,glycosylation sites could be divided into three different types based on gene sequences and conservative domains.Two of them,type I and type II protein,were α-type soluble proteinases,and the secondary structure of type III proteinase was rich in random coil and has potential signal peptide,but they all did not have transmembrane helical structure.The result of tertiary structure prediction indicated that type I protein and type II protein were similar,they were all composed of α-helix and horizontal β-folded layers,but in the type III protein the α-helixes locateed in the lateral ends and were connected by vertical β-folded layers.