Tyr320 is a molecular determinant of the catalytic activity of β-glucosidase from Neosartorya fischeri

Research output: Contribution to journalJournal articleResearchpeer-review

  • Ramasamy Shanmugam
  • In Won Kim
  • Tiwari, Manish Kumar
  • Hui Gao
  • Primata Mardina
  • Devashish Das
  • Anurag Kumar
  • Marimuthu Jeya
  • Sang Yong Kim
  • Young Sin Kim
  • Jung Kul Lee

β-Glucosidases (BGL) are key members of the cellulase enzyme complex that determine efficiency of lignocellulosic biomass degradation, which have shown great functional importance to many biotechnological systems. A previous reported BGL from Neosartorya fischeri (NfBGL) showed much higher activity than other BGLs. Screening the important residues based on sequence alignment, analyzing a homology model, and subsequent alteration of individually screened residues by site-directed mutagenesis were carried out to investigate the molecular determinants of the enzyme's high catalytic efficiency. Tyr320, located in the wild-type NfBGL substrate-binding pocket was identified as crucial to the catalytic function of NfBGL. The replacement of Tyr320 with aromatic amino acids did not significantly alter the catalytic efficiency towards p-nitrophenyl β-D-glucopyranoside (pNPG). However, mutants with charged and hydrophilic amino acids showed almost no activity towards pNPG. Computational studies suggested that an aromatic acid is required at position 320 in NfBGL to stabilize the enzyme-substrate complex formation. This knowledge on the mechanism of action of the molecular determinants can also help rational protein engineering of BGLs.

Original languageEnglish
JournalInternational Journal of Biological Macromolecules
Volume151
Pages (from-to)609-617
Number of pages9
ISSN0141-8130
DOIs
Publication statusPublished - 15 May 2020

    Research areas

  • Catalytic efficiency, MD simulation, Substrate affinity, β-Glucosidase, π-Sigma interaction

ID: 237412050