Comparison of amino acid sequences of the trypsin inhibitors from taro (Colocasia esculenta), giant taro (Alocasia macrorrhiza) and giant swamp taro (Cyrtosperma chamissonis)

• Published in: Biochemistry and molecular biology international Vol. 31; no. 1; pp. 73 - 81
• Main Authors: Peng, L, Bradbury, J.H, Hammer, B.C, Shaw, D.C
• Format: Journal Article
• Language: English
• Published: England 01.09.1993
• Subjects: Alocasia macrorrhizos; Amino Acid Sequence; amino acid sequences; Chromatography, High Pressure Liquid; Colocasia esculenta; comparisons; Cyrtosperma; Molecular Sequence Data; Plant Proteins - chemistry; Plant Proteins - genetics; Plants - chemistry; Polymorphism, Genetic; sequence homology; Sequence Homology, Amino Acid; trypsin inhibitors; Trypsin Inhibitors - chemistry; Trypsin Inhibitors - genetics
• ISSN: 1039-9712

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 die 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 M 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 Pl site for the trypsin inhibitors of aroids is different from that of other Kunitz-type inhibitors and could be at Leu56.