Cationic Inhibitors of Serine Proteinases from Buckwheat Seeds: Study of Their Interaction with Exogenous Proteinases

T. A. Tsybina¹, Y. E. Dunaevsky¹, N. A. Popykina², N. I. Larionova², and M. A. Belozersky^1*

¹Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119992, Russia; fax: (7-095) 939-3181; E-mail: mbeloz@belozersky.msu.ru

²Faculty of Chemistry, Lomonosov Moscow State University, Moscow 119992, Russia; fax: (7-095) 939-0997; E-mail: nilar@enzyme.chem.msu.su

^* To whom correspondence should be addressed.

Received July 24, 2003

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The inhibition of exogenous serine proteinases of different origin by cationic protease inhibitors BWI-1c, -2c, -3c, and -4c from buckwheat (Fagopyrum esculentum Moench) seeds has been studied. High efficiency of the inhibitors in binding bovine trypsin and chymotrypsin as well as their broad antiprotease effect, including inhibition of proteinases secreted by fungi and bacteria, has been demonstrated. According to the data obtained, it is proposed that cationic inhibitors from buckwheat seeds may participate in the defense of plants against fungal and bacterial infection.

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KEY WORDS: inhibitors of serine proteinases, inhibition constant, trypsin, subtilisin, chymotrypsin

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