The specificity of an aminopeptidase affects its performance in hydrolyzing peanut protein isolate and zein. (March 2019)

• Record Type: Journal Article
• Authors: Lei, Fenfen; Hu, Chuanrong; Zhang, Ni; He, Dongping
• Is Part Of: Lebensmittel-Wissenschaft + Technologie =. Volume 102(2019)
• Page Start: 37
• Page End: 44
• Publication Date: 2019-03
• Subjects: Aminopeptidase -- Substrate specificity -- Protein hydrolysis -- Amino acid composition -- Bioactivity; Food industry and trade -- Periodicals; Food -- Composition -- Periodicals; Microbiology -- Periodicals; Nutrition -- Periodicals; 664.005
• DOI: 10.1016/j.lwt.2018.10.041
• Languages: English
• ISSNs: 0023-6438

Abstract

Abstract: To explore how the substrate specificity of an aminopeptidase (Leu > Glu, Gly, Ala, Val (PreII)) from Bacillus licheniformis SWJS33 (BLAM) affects its performance in hydrolyzing different proteins, peanut protein isolate (PPI) and zein which containing 6.8% and 18.7% Leu respectively were employed as substrates. BLAM increased the degree of hydrolysis of zein more effectively than that of PPI. The aminopeptidase could significantly increase the percentages of Leu and PreII in total free amino acid compared to commercial peptidases. The amino acid compositions of both PPI and zein bioactive peptides were changed by BLAM. BLAM promoted the antioxidant activity of PPI and zein hydrolysates significantly, and decreased the IC50 of ACE-inhibitory activity of zein hydrolysates. Peptides identification suggested that the endoproteases used together with BLAM significantly affected polypeptides (longer than 6 amino acid) composition of the hydrolysates, and then further affected the catalysis efficiency of BLAM. BLAM had greater potential in hydrolyzing proteins with higher content of Leu and PreII. Highlights: The specificity of the aminopeptidase affected its efficiency in proteins hydrolysis. The aminopeptidase improved the degree of hydrolysis of zein more effectively. The aminopeptidase increased the release of Leu in both of the two hydrolysates. The aminopeptidase promoted the bioactivities of zein hydrolysates more effectively. The aminopeptidase preferred proteins rich in Leu, Glu, Gly, Ala and Val.