Rapid Quantitation of L-Glutamine Based on Recombined Blue Pigment Synthetase A

Abstract:

Objective The aim of this study is to determine the concentration of L-glutamine (Gln) in complex samples rapidly, economically, and accurately.Method A method for the rapid and precise quantification of Gln was developed based on the blue pigment synthetase A (BpsA) expressed by recombinant Escherichia coli (E.coli). The holoenzyme holo-BpsA was obtained by activating apo-BpsA in vitro and optimizing the measurement conditions.Result The obtained holo-BpsA can complete quantitative determination within 30 min under suitable conditions. The method showed the limit of detection being 10.46 μmol/L, the limit of quantification being 31.68 μmol/L, the interplate standard deviation of 1.41 μmol/L, and the intraplate standard deviation of 0.85 μmol/L. The average spiked recovery rate for five commonly used culture media varied between 94.7% and 106.6%, with the standard deviation mostly below 5%. There was no significant change in the enzyme activity after holo-BpsA was stored at -20 ℃ for two months.Conclusion The method developed for rapid quantitation of Gln based on BpsA is simple to operate, highly specific, and time-saving and has high sensitivity and accuracy.