Primary structure and allergenic activity of trypsin inhibitors from the seeds of buckwheat (Fagopyrum esculentum Moench).
The complete amino acid sequences of two trypsin inhibitors BWI-2a and BWI-2b from the seeds of buckwheat (Fagopyrum esculentum Moench) were determined. BWI-2b consists of 51 amino acid residues containing two disulfide bonds. BWI-2a shares all amino acids with BWI-2b except for the C-terminal tripeptide: BWI-2a lacks Glu-Gly-Asn and ends with the Asp residue, making a total of 48 residues in the chain. The two disulfide bonds connect Cys11 to Cys32 and Cys15 to Cys28. BWI-2b shows no relatedness to the other buckwheat trypsin inhibitor reported [Belozersky et al. (1995) FEBS Lett. 371, 264-266]. Sequence comparison of BWI-2b with those of the other proteins included in PIR showed that BWI-2b is significantly homologous to the N-terminal region of storage proteins classified in the vicilin family. Furthermore, the allergenic activity of BWI-2b and the other buckwheat trypsin inhibitor BWI-1 was examined using the radioallergosorbent test. The result indicated that both inhibitors BWI-2b and BWI-1 have IgE binding activity, albeit to a low extent, suggesting that they might be minor allergenic proteins in buckwheat seeds.
Park
S S
SS
Laboratory of Biochemistry, Faculty of Agriculture, Kyushu University, Fukuoka, Japan. pakss@agr.kyushu-u.ac.jp
Abe
K
K
Kimura
M
M
Urisu
A
A
Yamasaki
N
N
D000485:Allergens / Q000737:chemistry* / Q000276:immunology / Q000302:isolation & purification; D000595:Amino Acid Sequence; D052179:Antigens, Plant; D004220:Disulfides / Q000737:chemistry; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000737:chemistry* / Q000276:immunology / Q000302:isolation & purification; D006109:Poaceae / Q000737:chemistry* / Q000276:immunology; D011852:Radioallergosorbent Test; D012639:Seeds / Q000737:chemistry; D017386:Sequence Homology, Amino Acid; D014361:Trypsin Inhibitors / Q000737:chemistry* / Q000276:immunology / Q000302:isolation & purification
D000485:Allergens; D052179:Antigens, Plant; C095816:BWI-1 protein, Fagopyrum esculentum; C103575:BWI-2 protein, Fagopyrum esculentum; D004220:Disulfides; D010940:Plant Proteins; D014361:Trypsin Inhibitors