Characterization of 2-deoxyribose-5-phosphate aldolase from Bacillus altitudinis JYY-02.

Abstract

HMG-CoA reductase inhibitors, commonly known as statins, effectively reduce low-density lipoprotein cholesterol levels in the blood, thereby playing a key role in the treatment of cardiovascular and cerebrovascular diseases. The biosynthesis of the compounds can be achieved via deoxyriboaldolase. In this study, a 672-bp gene coding 2-deoxyribose-5-phosphate aldolase (DERA) was identified from the genome of Bacillus altitudinis JYY-02 and overexpressed in Escherichia coli BL21(DE3). The recombinant DERA exhibited a molecular weight of 23.15 kDa and was purified by Ni-NTA affinity chromatography with a 12.9-fold increase in purity and a final yield of 51.2%. Molecular docking analysis revealed that Lys, Leu, Thr, Ser, and Gly are the key amino acid residues involved in the interaction between DERA and its substrate, 2-deoxyribose-5-phosphate. The effects of pH, temperature, and metal ions on enzyme activity were investigated. The optimal pH and temperature for activity were pH7.0 and 45 °C, respectively. Using 2-deoxyribose-5-phosphate as the substrate, the Vmax and the Km values were calculated as 6.978 µmol/mg·pr/min and 8.398 mM, respectively. Thermal stability assays showed that the enzyme retained 79% and 39% of its initial activity after 1 h of incubation at 60 °C and 90 °C respectively. Bioassay of acetaldehyde tolerance of DERA revealed that DERA retained 77.5%, 55.6%, and 34.7% activity after treatment with 100, 200 and 300 mM acetaldehyde for 2 h, respectively. Furthermore, using acetaldehyde and chloroacetaldehyde as substrates, DERA catalyzed the formation of S-4-chloro-3-hydroxybutyraldehyde (S-CHBAL), indicating its potential for application in the biosynthesis of statin intermediates.