TY - JOUR
T1 - Enzymatic synthesis of Theanine with L-glutamine-Zn(II) complexes
AU - Wang, Hao Qi
AU - Yao, Zhong
AU - Zhou, Zhi
AU - Sun, Yun
AU - Wei, Ping
AU - Ouyang, Pingkai
PY - 2012/11
Y1 - 2012/11
N2 - Theanine, a unique amino acid found in tea plants, has many important physiological functions. Theanine can be enzymatically synthesized via the γ-glutamyltranspeptidation reaction. In this study, we described a new method of theanine synthesis using the L-glutamine-Zn(II) (Zn(Gln)2) complex instead of glutamine as the donor, which successfully reduced the side autotranspeptidation reaction and led to higher yield of theanine. We prepared the Zn(Gln)2 complexes and showed that they are stable in liquid bulk under 9.0 pH. After using the Zn(Gln)2 in the γ- glutamyltranspeptidation reaction, we utilized HPLC and Mass spectrometry analysis to demonstrated that Zn(Gln)2 was an more effective γ-glutamyl donor than glutamine. The autotranspeptidation reaction was restrained effectively. As a result, the theanine yield and the conversion rate for glutamine were vastly improved. In a reaction mixture containing 48 mM of Zn(Gln)2, 1.6 M ethylamine, and 0.5 U/mL GGT, the final concentration of theanine obtained was 61.3 mM after incubation at 37°C for three hours. The conversion rate for glutamine was 63.8%, which showed a 16.9% increase as compared to when using glutamine alone as the donor substrate.
AB - Theanine, a unique amino acid found in tea plants, has many important physiological functions. Theanine can be enzymatically synthesized via the γ-glutamyltranspeptidation reaction. In this study, we described a new method of theanine synthesis using the L-glutamine-Zn(II) (Zn(Gln)2) complex instead of glutamine as the donor, which successfully reduced the side autotranspeptidation reaction and led to higher yield of theanine. We prepared the Zn(Gln)2 complexes and showed that they are stable in liquid bulk under 9.0 pH. After using the Zn(Gln)2 in the γ- glutamyltranspeptidation reaction, we utilized HPLC and Mass spectrometry analysis to demonstrated that Zn(Gln)2 was an more effective γ-glutamyl donor than glutamine. The autotranspeptidation reaction was restrained effectively. As a result, the theanine yield and the conversion rate for glutamine were vastly improved. In a reaction mixture containing 48 mM of Zn(Gln)2, 1.6 M ethylamine, and 0.5 U/mL GGT, the final concentration of theanine obtained was 61.3 mM after incubation at 37°C for three hours. The conversion rate for glutamine was 63.8%, which showed a 16.9% increase as compared to when using glutamine alone as the donor substrate.
KW - Autotranspeptidation
KW - Enzymatic synthesis
KW - L-glutamine-Zn(II)
KW - Theanine
KW - γ-glutamyltranspeptidase
UR - http://www.scopus.com/inward/record.url?scp=84879967986&partnerID=8YFLogxK
U2 - 10.1007/s12257-012-0205-0
DO - 10.1007/s12257-012-0205-0
M3 - 文章
AN - SCOPUS:84879967986
SN - 1226-8372
VL - 17
SP - 1135
EP - 1139
JO - Biotechnology and Bioprocess Engineering
JF - Biotechnology and Bioprocess Engineering
IS - 6
ER -