title: Amino acid sequence of the protease inhibitor BWI-4a from buckwheat seeds.
abstract: The complete amino acid sequence of protease inhibitor BWI-4a from buckwheat (Fagopyrum esculentum Moench) seeds, consisting of 67 amino acid residues with a single disulfide bond, has been established by Edman degradation in combination with matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Its N terminus is blocked by a pyroglutamic acid residue. Mass spectrometric analysis revealed that inhibitor BWI-4a is present in buckwheat seeds in two isoforms with a single amino acid substitution of Ala40 for Gly40. The reactive site of the inhibitor contains an Arg43-Asp44 bond. Analysis of the amino acid sequence suggests that the buckwheat seed protease inhibitor is a member of the potato proteinase inhibitor I family.
authors.affiliation: AN Belozersky Institute of Physico-Chemical Biology, Moscow State University, Russian Federation. mbeloz@genebee.msu.su
authors.forename: M A
authors.initials: MA
authors.lastname: Belozersky
authors.forename: Y E
authors.initials: YE
authors.lastname: Dunaevsky
authors.forename: A K
authors.initials: AK
authors.lastname: Musolyamov
authors.forename: T A
authors.initials: TA
authors.lastname: Egorov
mesh_terms: D000409:Alanine / Q000737:chemistry; D000595:Amino Acid Sequence; D001665:Binding Sites; D002918:Chymotrypsin / Q000378:metabolism; D004220:Disulfides; D019612:Fagopyrum / Q000737:chemistry*; D005998:Glycine / Q000737:chemistry; D007930:Leucine / Q000737:chemistry; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry; D010940:Plant Proteins / Q000737:chemistry*; D020033:Protein Isoforms; D011761:Pyrrolidonecarboxylic Acid / Q000737:chemistry; D017386:Sequence Homology, Amino Acid; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014357:Trypsin / Q000378:metabolism; D014361:Trypsin Inhibitors / Q000737:chemistry / Q000494:pharmacology
chemical_list: D004220:Disulfides; D010455:Peptides; D010940:Plant Proteins; D020033:Protein Isoforms; D014361:Trypsin Inhibitors; C418628:buckwheat inhibitor 4a; C023578:proteinase inhibitor I (plants); D002918:Chymotrypsin; D014357:Trypsin; D007930:Leucine; D000409:Alanine; D011761:Pyrrolidonecarboxylic Acid; D005998:Glycine