Protein-coated microcrystals of Prunus armeniaca hydroxynitrile lyase: an effective and recyclable biocatalyst for synthesis of (R)-mandelonitrile


CHEMICAL PAPERS, vol.73, no.1, pp.185-193, 2019 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 73 Issue: 1
  • Publication Date: 2019
  • Doi Number: 10.1007/s11696-018-0577-5
  • Title of Journal : CHEMICAL PAPERS
  • Page Numbers: pp.185-193


In this study, the crude solution of Prunus armeniaca hydroxynitrile lyase (ParsHNL) was simultaneously precipitated onto K2SO4 salt in acetone to immobilize ParsHNL as protein-coated microcrystals and the obtained preparations (PCMCs-ParsHNL) were used for the synthesis of (R)-mandelonitrile in buffer-saturated methyl tert-butyl ether (pH 4.0). The yield and enantiopurity of (R)-mandelonitrile were 100 and 90.5%, respectively, for free HNL, whereas the corresponding yield and enantiopurity values were 100 and 99.8%, respectively, for PCMCs-ParsHNL after 96h reaction time. The free HNL and PCMCs-ParsHNL were stored at room temperature and 5 degrees C during 30days and the results showed that PCMCs-ParsHNL had better storage stability compared to the free HNL at both room temperature and 5 degrees C. PCMCs-ParsHNL was imaged by a scanning electron microscopy and PCMCs-ParsHNL was rectangular in shape. PCMCs-ParsHNL was recycled five times in the synthesis of (R)-mandelonitrile and 75.2% initial activity recovery and 99.8% enantiomeric excess for (R)-mandelonitrile was determined after five uses. Thus, immobilizing ParsHNL as PCMCs provided highly active and reusable HNL preparations for (R)-mandelonitrile synthesis in buffer-saturated methyl tert-butyl ether.