Mining and Characterization of Thermophilic Glucose Isomerase Based on Virtual Probe Technology

Identification of hyperthermophilic D-allulose 3-epimerase from Thermotoga sp. and its application as a high-performance biocatalyst for D-allulose synthesis

D-Allulose 3-epimerase (DAE) is a vital biocatalyst for the industrial synthesis of D-allulose, an ultra-low calorie rare sugar. However, limited thermostability of DAEs hinders their use at high-temperature production. In this research, hyperthermophilic TI-DAE (Tm = 98.4 ± 0.7 ℃) from Thermotoga sp. was identified via in silico screening. A comparative study of the structure and function of site-directed saturation mutagenesis mutants pinpointed the residue I100 as pivotal in maintaining the high-temperature activity and thermostability of TI-DAE. Employing TI-DAE as a biocatalyst, D-allulose was produced from D-fructose with a conversion rate of 32.5%. Moreover, TI-DAE demonstrated excellent catalytic synergy with glucose isomerase CAGI, enabling the one-step conversion of D-glucose to D-allulose with a conversion rate of 21.6%. This study offers a promising resource for the enzyme engineering of DAEs and a high-performance biocatalyst for industrial D-allulose production.

Ensure the accuracy and consistency of biochemical analyzer test results: Chemometrics for instrument and inter-instrument item comparison in Chinese hospital laboratory

Biochemical analyzers are vital instruments that utilize the principle of photoelectric colorimetry to quantify a specific chemical composition in body fluids. This analysis provides critical data for the diagnosis, treatment, prognosis, and overall health status of various diseases in clinical practice. However, the performance of a biochemical analyzer can vary significantly between different brands or over time within the same brand. Therefore, it is imperative to regularly assess the performance of the analyzer to ensure consistent results for longitudinal studies and to maintain day-to-day data consistency. Additionally, when multiple analyzers are utilized, it is necessary to evaluate the performance of each instrument to ensure accurate results across multiple platforms. In this study, we developed and verified an experimental evaluation scheme for the analytical performance of the instrument, chemometrics for biochemical analyzers, utilizing national reference materials and patient sera as the experimental subjects. We evaluated the performance of the optical system, temperature control system, sample-adding system, and detection system to confirm the feasibility of this scheme. We also compared the analytical performance of different brands of biochemical analyzers for routine biochemical tests, such as liver function, kidney function, ion, blood lipids, blood glucose, and myocardial enzyme spectrum. Using the AU 5400 as a control and the ADVIA 2400 as the comparison system, the relative variation in inter-instrument comparison data was found to be acceptable at the clinical medicine decision level. In conclusion, the performance of a biochemical analyzer can vary significantly between different brands or over time within the same brand. Regular evaluations are necessary to ensure accurate and consistent results across different analyzers. This study provides a feasible scheme for evaluating the analytical performance of biochemical analyzers that can be used to ensure the accuracy and consistency of the results of different brands of automatic chemical analyzers in the laboratory.