Biochemical characterization of a Kunitz inhibitor from Inga edulis seeds with antifungal activity against Candida spp.
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We describe the characterization of IETI, the first trypsin inhibitor purified from Inga edulis, a tree widely distributed in Brazil. Two-step chromatography was used to purify IETI, a protein composed of a single peptide chain of 19,685.10 Da. Amino-terminal sequencing revealed that IETI shows homology with the Kunitz family, as substantiated by its physical–chemical features, such as its thermal (up to 70 °C) and wide-range pH stability (from 2 to 10), and the value of its dissociation constant (6.2 nM). IETI contains a single reactive site for trypsin, maintained by a disulfide bridge; in the presence of DTT, its inhibitory activity was reduced in a time- and concentration-dependent manner. IETI presented activity against Candida ssp., including C. buinensis and C. tropicalis. IETI inhibitory activity triggered yeast membrane permeability, affecting cell viability, thus providing support for the use of IETI in further studies for the control of fungal infections.
KeywordsTrypsin inhibitor Membrane permeability Candida tropicalis Candida buinensis
This work was supported by CNPq (407127/2013-5), CAPES and FINEP.
- Bhattacharyya A, Babu CR (2009) Purification and biochemical characterization of a serine proteinase inhibitor from Derris trifoliata Lour. seeds: insight into structural and antimalarial features. Phytochemistry 70:703–712. https://doi.org/10.1016/j.phytochem.2009.04.001 CrossRefPubMedGoogle Scholar
- Migliolo L, de Oliveira AS, Santos EA, Franco OL, de Sales MP (2010) Structural and mechanistic insights into a novel non-competitive Kunitz trypsin inhibitor from Adenanthera pavonina L. seeds with double activity toward serine- and cysteine-proteinases. J Mol Graph Model 29:148–156. https://doi.org/10.1016/j.jmgm.2010.05.006 CrossRefPubMedGoogle Scholar
- Richardson M, Campos FAP, Xavier-Filho J, Macedo MLR, Maia GMC, Yarwood A (1986) The amino acid sequence and reactive (inhibitory) site of the major trypsin isoinhibitor (DE5) isolated from seeds of the Brazilian Carolina tree (Adenanthera pavonina L.). Biochim Biophys Acta (BBA) Protein Struct Mol Enzymol 872:134–140. https://doi.org/10.1016/0167-4838(86)90156-1 CrossRefGoogle Scholar