Protease inhibitors in buckwheat seeds: Comparison of anionic and cationic inhibitors

Autor: Tatjana A. Tsybina, T. N. Gruban, Yakov E. Dunaevsky, Mikhail A. Belozersky, Ekaterina B. Pavlukova, G. A. Beliakova
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Zdroj: ResearcherID
Popis: Summary Protease inhibitors in buckwheat seeds are separated into two main groups — anionic and cationic inhibitors, according to their behaviour on ion-exchange chromatography. Three anionic inhibitors (BWI-la, BWI-2a and BWI-4a) and two cationic (BWI-2c and BWI-4c) were purified to homogeneity and characterized. Molecular masses of anionic inhibitors were in the range 7.7–9.2 kD and of cationic 6.0 kD. Both anionic and cationic inhibitors were highly pH- and thermostable. All anionic and cationic inhibitors inhibited trypsin. In addition to trypsin BWI-la and BWI-2a inhibited chymotrypsin, however, less effectively. Cationic inhibitor BWI-4c besides trypsin and chymotrypsin inhibited also bacterial subtilisin. Inhibitors BWI-la, BWI-2a, BWI-4a and BWI-2c contain an Arg residue at the reactive site whereas BWI-4c contains a Lys residue. According to determined amino acid sequences anionic inhibitors BWI-1a, BWI-2a and BWI-4a belong to the potato proteinase inhibitor I family.
Databáze: OpenAIRE