Open AccessThe application of L‐glutaminase for the synthesis of the immunomodulatory γ ‐D‐glutamyl‐L‐tryptophan and the kokumi‐imparting γ ‐D‐glutamyl peptides
Author(s) -
Yang Juan,
Huang Yuran,
Dong Hao,
Huang Guiying,
Yu Limei,
Bai Weidong,
Zeng Xiaofang
Publication year - 2020
Publication title -
food science and nutrition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.614
H-Index - 27
ISSN - 2048-7177
DOI - 10.1002/fsn3.1845
Subject(s) - tryptophan , chemistry , yield (engineering) , glutaminase , stereochemistry , bacillus amyloliquefaciens , biochemistry , glutamine , amino acid , fermentation , materials science , metallurgy
Abstract Glutaminase of Bacillus amyloliquefaciens has been used to synthesize the immunomodulatory γ ‐D‐glutamyl‐L‐tryptophan ( γ ‐D‐Glu‐L‐Trp) and the kokumi‐active γ ‐D‐glutamyl peptides. The optimum yield of γ ‐D‐Glu‐L‐Trp was 55.76 mM in corresponding to a minimum yield of by‐product ( γ ‐D‐Glu‐ γ ‐D‐Glu‐L‐Trp) in the presence of 75 mM D‐Gln and 100 mM L‐Trp. The glutaminase has a low K m values for the donors (D‐Gln and L‐Gln:5.53 and 0.98 mM), but high ones for the acceptors (L‐Trp, L‐Phe, L‐Met, L‐Val and γ ‐[D‐Glu] ( n =1,2,3) ‐L‐Val/L‐Phe/L‐Met, ranging from 32.51 to 193.05 mM). The highest K m value appearing when n = 2 ( γ ‐[D‐Glu] ( n =0,1,2) ‐L‐Val/L‐Phe/L‐Met) suggested the rising difficulty for synthesis when the number of donor increases in the reaction mixtures. The γ ‐[D‐Glu] ( n =1,2,3) ‐L‐Val/L‐Phe/L‐Met at 5 mM can impart the blank chicken broth an enhancing monthfulness, thickness, and umaminess taste.