Inhibition of bovine α-chymotrypsin by cyclic trypsin inhibitor SFTI-1 isolated from sunflower seeds and its two acyclic analogues.

Autor: Zabłotna, Ewa, Kaźmierczak, Katarzyna, Jaśkiewicz, Anna, Kupryszewski, Gotfryd, Rolka, Krzysztof
Zdroj: Letters in Peptide Science; Mar2002, Vol. 9 Issue 2/3, p131-134, 4p
Abstrakt: Trypsin inhibitor SFTI-1 isolated from sunflower seeds (comprising 14 amino acid residues and two cycles: head-to-tailcyclisation and disulfide bridge) is the smallest naturally occurring plant serine proteinase inhibitor. In our recent paperwe have shown that the elimination head-to-tail cyclisation did not change trypsin inhibitory activity as judged by measuredby association equilibrium constants K. The removal of disulfide bridge produced 2.4-fold lower activity. In the present paper we described chymotrypsin inhibitory activity. SFTI-1 inhibits significantly lower bovine α-chymortypsin(K = (5.20±1.56) × 10 M). The activity of the analogue with disulfide bridge only was practically the same, whereas the K value determined forhomodetic peptide was almost 3-fold lower. Considering the results obtained and the recent literature data we postulate thelower inhibitory activity against both enzyme of the analogue with head-to-tail cyclisation only reflect its lower proteolytic stability. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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