In silico assessment: Suggested homology of chickpea (Cicer arietinum L.) legumin and prediction of ACE-inhibitory peptides from chickpea proteins using BLAST and BIOPEP analyses

Three protein sequences, chickpea legumin α- and β-subunits [Cicer arietinum] (NCBI accession number: gi|6273402), oat 12S seed storage globulin 1 (NCBI accession number: gi|134918) and rice glutelin precursor [Oryza sativa (japonica cultivar-group)] (NCBI accession number: gi|62546207) were chosen for sequence alignments using BLAST analysis. The sequence alignments gave approximately 30% similarity of AA sequences with chickpea legumin vs. oat 12S globulin 1 and chickpea legumin vs. rice glutelin precursor; the oat 12S globulin 1 and rice glutelin precursor exhibited relatively high sequence homology of 63%. In silico, BIOPEP results showed that the chickpea legumin and provicilin precursor demonstrated either di- or tri-peptides with a total of 177 and 133 potential angiotensin I-converting enzyme (ACE) inhibitory peptides, respectively. Ficain and proteinase K were the proposed proteases that could theoretically release greater numbers of predicted ACE-inhibitory peptides (34 and 35, respectively) from chickpea legumin and provicilin precursor; in addition, the simulation of human gastrointestinal digestion using a combination of pepsin, trypsin and chymotrypsin A could liberate a sum of 23 predicted ACE-inhibitory peptides from these two proteins.

► Chickpea protein sequences were examined by BLAST and BIOPEP analyses. ► Chickpea legumin showed 30% of AA sequence homology to oat 12S globulin 1. ► Oat 12S globulin 1 and rice glutelin precursor shared AA sequence homology of 63%. ► Chickpea globulin precursors showed 133 to 177 potential ACE-inhibitory peptides.