Characterization of α-hairpinin in the genome of lima bean (Phaseolus lunatus)

Abstract

Antimicrobial α-Hairpinin peptides are sources of bioactive molecules with significant structural diversity and various biological activities. Phaseolus lunatus, known as lima bean, is a plant from the Fabaceae family, native to Central and South America. It is the second most important legume agronomically and economically in tropical regions, after the common bean. Due to its importance, several omics studies have been recently conducted on this species. The research aimed to characterize the antimicrobial peptides of the α-hairpinin family in the lima bean genome by analyzing their physicochemical properties, in silico biological activities, and three-dimensional structure. To this end, α-hairpinin sequences were identified according to the cysteine pattern characteristic of this protein family. After target identification, a search for conserved domains, signal peptides, and subcellular localization was conducted. Molecular mass, isoelectric point, grand average of hydropathicity (GRAVY), and biological activities were also analyzed, and a three-dimensional model of the candidate was generated. Following the mining process, an α-hairpinin sequence from P. lunatus (PlHrp1) was identified. PlHrp1 consisted of 41 amino acids, was predicted to be in the extracellular region, had an isoelectric point of 6.28, a mass of 4.81 kDa, and a gravy of -1.078. The alignment revealed that PlHrp1 contained the 4 conserved cysteine residues. In silico activity analyses demonstrated that PlHrp1 exhibited antifungal and antibacterial activities, with no antiviral activity. The secondary structure displayed two antiparallel α-helices connected by a loop. The model described 94.4% of amino acid residues in favorable positions. This study provides a comprehensive analysis of α-hairpinin peptides in the Phaseolus lunatus genome, highlighting the presence of this peptide family in the lima bean species and offering insights into their potential.