Peng L, Bradbury J H, Hammer B C, Shaw D C
Division of Botany & Zoology, Australian National University, Canberra.
Biochem Mol Biol Int. 1993 Sep;31(1):73-81.
The amino acid sequences of the trypsin inhibitors from taro Colocasia esculenta var. esculenta and giant swamp taro Cyrtosperma chamissonis have been determined and are compared with the protein sequence of the trypsin/chymotrypsin inhibitor from giant taro Alocasia macrorrhiza. Both inhibitors display polymorphism and there is evidence of two components in the giant swamp taro. The positional identity between the proteins is highest at 73-75% for the comparison of the giant taro (GT) with the polymorphic forms of the taro (T) inhibitors and lowest at 56-58% for the pairs of taro and giant swamp taro (GST) proteins. The comparisons show that the inhibitors from T and GT are more related to each other than to GST, which supports their taxonomic classification into different tribes. Location of the P1 site for the trypsin inhibitors of aroids is different from that of other Kunitz-type inhibitors and could be at Leu56.
已测定芋头（Colocasia esculenta var. esculenta）和野芋（Cyrtosperma chamissonis）中胰蛋白酶抑制剂的氨基酸序列，并将其与海芋（Alocasia macrorrhiza）中胰蛋白酶/糜蛋白酶抑制剂的蛋白质序列进行比较。两种抑制剂均表现出多态性，并且有证据表明野芋中有两种成分。将海芋（GT）与芋头（T）抑制剂的多态形式进行比较时，蛋白质之间的位置一致性最高，为73 - 75%；而芋头和野芋（GST）蛋白质对之间的位置一致性最低，为56 - 58%。比较结果表明，来自芋头（T）和海芋（GT）的抑制剂彼此之间的关系比与野芋（GST）的关系更为密切，这支持了它们被分类到不同族中的分类学观点。天南星科植物胰蛋白酶抑制剂的P1位点位置与其他库尼茨型抑制剂不同，可能位于Leu56处。
