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


YILDIRIM D., TOPRAK A., ALAGÖZ D., TÜKEL S. S.

CHEMICAL PAPERS, vol.73, no.1, pp.185-193, 2019 (Peer-Reviewed Journal) identifier identifier

  • Publication Type: Article / Article
  • Volume: 73 Issue: 1
  • Publication Date: 2019
  • Doi Number: 10.1007/s11696-018-0577-5
  • Journal Name: CHEMICAL PAPERS
  • Journal Indexes: Science Citation Index Expanded, Scopus
  • Page Numbers: pp.185-193
  • Keywords: Hydroxynitrile lyase, Protein-coated microcrystals, Transcyanation, Enantiopure, Cyanohydrins, (R)-HYDROXYNITRILE LYASE, ENANTIOSELECTIVE SYNTHESIS, IMMOBILIZATION, CYANOHYDRINS, SEEDS, PURIFICATION, STABILITY

Abstract

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.