Characterisation, immunolocalisation and antifungal activity of a lipid transfer protein from chili pepper (Capsicum annuum) seeds with novel α‐amylase inhibitory properties

Abstract

Lipid transfer proteins (LTPs) were thus named because they facilitate the transfer of lipids between membranes in vitro. This study was triggered by the characterization of a 9-kDa LTP from Capsicum annuum seeds that we call Ca-LTP(1) . Ca-LTP(1) was repurified, and in the last chromatographic purification step, propanol was used as the solvent in place of acetonitrile to maintain the protein's biological activity. Bidimensional electrophoresis of the 9-kDa band, which corresponds to the purified Ca-LTP(1) , showed the presence of three isoforms with isoelectric points (pIs) of 6.0, 8.5 and 9.5. Circular dichroism (CD) analysis suggested a predominance of α-helices, as expected for the structure of an LTP family member. LTPs immunorelated to Ca-LTP(1) from C. annuum were also detected by western blotting in exudates released from C. annuum seeds and also in other Capsicum species. The tissue and subcellular localization of Ca-LTP(1) indicated that it was mainly localized within dense vesicles. In addition, isolated Ca-LTP(1) exhibited antifungal activity against Colletotrichum lindemunthianum, and especially against Candida tropicalis, causing several morphological changes to the cells including the formation of pseudohyphae. Ca-LTP(1) also caused the yeast plasma membrane to be permeable to the dye SYTOX green, as verified by fluorescence microscopy. We also found that Ca-LTP(1) is able to inhibit mammalian α-amylase activity in vitro.

Purification, biochemical characterization, and antimicrobial activity of a new lipid transfer protein from Coffea canephora seeds

“…Working on systemic acquired resistance, Maldonado et al (2002) showed that LTPs can also be directly related to defense signaling. Plant LTPs also show antimicrobial activity against a number of microorganisms, especially fungi (Diz et al, 2011;Zottich et al, 2011).…”

“…Since then, several LTPs with antimicrobial activity against fungi and bacteria have been isolated from various plants. Ca-LTP, isolated from the seeds of Capsicum annuum was able to inhibit the growth of the yeast Candida tropicalis by more than 70% (Diz et al, 2011). Zottich et al (2011) isolated an LTP called Cc-LTP from coffee beans, C. canephora, which was able to inhibit the growth of the yeast Candida albicans and promote morphological changes such as the formation of pseudohyphae in C. tropicalis.…”

Purification and characterization of a novel antifungal protein with antiproliferation and anti-HIV-1 reverse transcriptase activities from <italic>Peganum harmala</italic> seeds

“…Combination of ion exchange chromatography and gel filtration or HPLC methods have been commonly employed for isolating other nsLTPs [23,24,35,36]. The N-terminal sequence of PHP, ITCPQVTQSLAPCV PYLISG, resembles those of other nsLTPs.…”

Antimicrobial Peptides from Fruits and Their Potential Use as Biotechnological Tools—A Review and Outlook

“…LTPs can be expressed in fruits (Douliez et al, 2000; Carvalho and Gomes, 2007), and they may have an importance in plant survival, as well as in plant breeding (Salminen et al, 2016). Ca-LTP1, a peptide from chili pepper ( C. annuum L.) seeds with molecular mass of 9461 Da, exhibited strong activity against the fungus C. lindemunthianum, F. oxysporum, C. tropicalis , and C. albicans and of the yeasts S. cerevisiae, Schizosaccharomyces pombe , and Pichia membranifaciens (Diz et al, 2006, 2011; Cruz et al, 2010). The peptide was further described as causing the formation of pseudohyphae and membrane disruption in C. tropicalis , with 70% of inhibition rate (Diz et al, 2011), morphological changes in P. membranifaciens and C. albicans and inhibition of the glucose-stimulated acidification of the medium in S. cerevisiae (Diz et al, 2006; Cruz et al, 2010).…”