Purification and some properties of two protein proteinase inhibitors from the seeds of Sophora japonica L. f.
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DOI:
https://doi.org/10.15625/0866-7160/v25n3.6839Abstract
Using column chromatography on superdex-75, MonoS and PAGE methods allowed to separate two highly purified protein proteinase inhibitors from Sophora japonica seeds, named SJ-I and SJ-II. Each of them showed inhibitory activity against both trypsin and chymotripsin.
The molecular mass of both inhibitors were estimated around 16 kDa. However, they were different in pI value: 6.2 for SJ-I and 5.85 for SJ-II.
The heat stability of two inhibitors was also similar: after the treatment of inhibitors at 70oC for 3 min, TIA remained 40% and after 15 min, TIA completely lost.
All obtained data led to a suggestion that SJ-I and SJ-II were isoforms and might be a Bowman - Birk type double headed inhibitors of higher molecular mass.