Abstract
Angiotensin I-converting enzyme inhibitory (ACE-I) peptides derived from food sources have been extensively researched. These peptides can be derived during the germination process. This study investigated the ACE-I activity of lamtoro gung seeds during the germination process. This work used in vitro and in silico methodologies to address the research issues. Lamtoro gung seeds were germinated for 120 h. The sprouts exhibiting the highest ACE-I activity were assessed for low-molecular-weight (LMW) peptide content and molecular distribution. Subsequently, the peptide sequence of the peptide fraction with a 1－3.5 kDa molecular weight range was characterized using liquid chromatography-mass spectrometry. The peptide sequence with the highest support vector machine score was chosen for molecular docking simulation to examine the interaction between peptides and ACE. The sample germinated for 48 h had the highest ACE-I activity (70.62%) as confirmed by the increased amount of LMW peptides (<1 and 1－3.5 kDa). Forty peptide sequences with ACE-I activity were identified in the <1 to 3.5 kDa fractions. Two peptide sequences (VEIKVTVK and KNEVAINELK) were predicted to interact with the active site of ACE according to molecular docking simulations. This research suggests that germination could serve as an alternative method for producing functional food substances that act as antihypertensive agents.