Bioactive peptides are specific protein fragments that exhibit a positive effect on human body functions and conditions, such as antimicrobial, antithrombotic, antidiabetic, immunomodulatory, mineral binding and antioxidant activities. They are derived from natural proteins in food and nutraceutical ingredients as well as synthetic peptides, often modeled on functional regions of characterized proteins.
Biologically active peptides can be released from various dietary protein sources through hydrolysis processing under physical, chemical, or microbial fermentation conditions and have received increasing attention in the medical field due to their potent effects on controlling diseases such as hypertension and diabetes. They can also be obtained by recombinant methods using cloning and gene expression in microorganisms, such as E. coli, with the aim of optimizing the desired properties.
Peptides with antimicrobial activity can be produced by all organisms, including microorganisms, plants and animals. Among them, the peptide mastoparans are of special interest because of their potential to act as pore-forming agents in cell membranes. These peptides have shown to be highly effective against a wide range of Gram-positive bacteria.
In order to further improve the efficacy of antimicrobial peptides, the research on their structure-function relationships is particularly important. In this context, the peptide GpTx-1 (Ala5, Phe6, Leu26, and Arg28), which is widely distributed in South American tarantulas such as Grammostila porter and Grammostila rosea, was studied. It was found that the structural modification of this peptide resulted in significant changes in its ability to bind to the acetylcholinesterase (ACE) target, with increased selectivity for the NaV1.7 channel. This was attributed to the changes in the hydrogen bonding and hydrophobic interaction between the peptide and ACE.