title: Cationic inhibitors of serine proteinases from buckwheat seeds.
abstract: Preparations of low molecular weight protein inhibitors of serine proteinases have been obtained from buckwheat (Fagopyrum esculentum) seeds by chromatography of seed extract on trypsin-Sepharose 4B, Mono-Q, and Mono-S ion exchangers (FPLC regime). Their molecular masses, determined by mass spectrometry, were 5203 (BWI-1c), 5347 (BWI-2c), 7760 (BWI-3c), and 6031 daltons (BWI-4c). All of the inhibitors possess high pH- and thermal stability in the pH range 2-12. In addition to trypsin, BWI-3c and BWI-4c inhibited chymotrypsin and subtilisin-like bacterial proteases. The N-terminal sequences of all of the inhibitors were determined: BWI-1c (23 residues), BWI-2c (33 residues), BWI-3c (18 residues), and BWI-4c (20 residues). In their physicochemical properties and N-terminal amino acid sequences, the buckwheat seed trypsin inhibitors BWI-3c and BWI-4c appear to belong to potato proteinase inhibitor I family.
authors.affiliation: Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119899 Russia.
authors.forename: T A
authors.initials: TA
authors.lastname: Tsybina
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
authors.forename: M A
authors.initials: MA
authors.lastname: Belozersky
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D002412:Cations; D002846:Chromatography, Affinity; D002918:Chymotrypsin / Q000037:antagonists & inhibitors; D019612:Fagopyrum / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010455:Peptides / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D010940:Plant Proteins; D012639:Seeds / Q000737:chemistry; D017386:Sequence Homology, Amino Acid; D015842:Serine Proteinase Inhibitors / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D013381:Subtilisins / Q000037:antagonists & inhibitors; D014357:Trypsin / Q000187:drug effects
chemical_list: D000596:Amino Acids; C448307:BWI 3c peptide, Fagopyrum esculentum; C448306:BWI 4c peptide; D002412:Cations; D010455:Peptides; D010940:Plant Proteins; D015842:Serine Proteinase Inhibitors; D013381:Subtilisins; D002918:Chymotrypsin; D014357:Trypsin