Purification and Characterization of a Non-Specific Lipid Transfer Protein 1 (nsLTP1) from Local Coffee Beans (Coffea arabica)

Plant non-specific lipid transfer proteins 1 (nsLTP1) are small and basic proteins. In vitro studies showed that nsLTP1 facilitates lipid binding and transfer, so it is presumably related to the formation of cutin. According to the previous other study, a novel nsLTP, named CcLTP1 purified from Brazil Coffea canephora seeds, exhibited the unique mammalian α-amylase inhibitory and antifungal properties. However, the biochemical and biophysical characterization of CcLTP1 are still unclear. The aims of our research are to characterize nsLTP1 from Taiwan local Coffea arabica and to elucidate the potential relationship between the biological functions and the protein structure. Two isoforms of nsLTP1 with the molecular mass of 9.3 kDa, named nsLTP1A and nsLTP1B were purified from local Coffea arabica. The N-terminal 18-amino acids of nsLTP1A, ITCQQVTHELEPCVPYLT, were identified and exhibited a unique nsLTP pattern. Circular dichroism analysis suggested both isoforms have α-helical conformation with high protein stability. The mixture of nsLTP1A and nsLTP1B exhibited antifungal effect toward Candida tropicalis and Candida albicans, however, the lipid transfer abilities of both isoforms were different. Unlike the study of Brazil Coffea canephora, both isoforms possessed no inhibitory activity against mammalian α-amylase activity. Finally, we have successfully purified, identified and evaluated the characteristics of Coffea arabica nsLTP1A and nsLTP1B in this study. cDNA sequence of local Coffea arabica nsLTP1 has also been identified.