從花豆中選殖出一種編碼Bowman–Birk型蛋白酶抑制劑的基因

Cloning of a Gene Encoding Bowman–Birk Type Protease Inhibitor from Phaseolus Coccineus

利用不同的豆科植物已選殖出的Bowman-Birk型蛋白酶抑制劑基因序列，作為核苷酸相似性比對，找出其相似度最高的部分作為引子的設計，再以花豆（Phaseolus coccineus）葉子所萃取的genomic DNA當作模板進行聚合酶連鎖反應，選殖出一種花豆Bowman-Birk型蛋白酶抑制劑（Phaseolus coccineus trypsin inhibitor；PCTI）基因，PCTI基因含有324 bp，可編碼出一條含有107個胺基酸的多胜肽鏈，基因內不含內含子（intron）。與其它Bowman-Birk型蛋白酶抑制劑家族比較胺基酸排列序列，具有高度的相同度（57%~88%）。親緣關係樹分析顯示，PCTI 與Phaseolus microcarpus 的Bowman-Birk型蛋白酶抑制劑親緣關係最親近。利用SWISS模型預測PCTI二級和3D結構模型。

Bowman-Birk type protease inhibitor gene sequences which have been cloned from different leguminous species were used for nucleotide similarity comparison to find the part with the greatest similarity and to use it as the primer design. Then genomic DNA extracted from the leaves of Phaseolus coccineus was used as the template to conduct a polymerase chain reaction, in order to clone the gene sequence of trypsin inhibitor in P. coccineus. The PCTI gene contains 324 bp, which can encode a polypeptide chain containing 107 amino acids without introns. Compared with other Bowman-Birk type protease inhibitor families, the amino acid sequence has a high degree of identity (57%~88%). The phylogenetic tree analysis shows that PCTI is the closest to the Bowman-Birk protease inhibitor of Phaseolus microcarpus. Use the SWISS model to predict PCTI secondary and 3D structural models.