Enzymatic Properties and Structural Insights Into the Derhamnosylating Alkaline α‐<scp>l</scp>‐Rhamnosidase From <i>Aspergillus flavus</i>
α-l-Rhamnosidases are ubiquitous enzymes responsible for derhamnosylation of α-l-rhamnose moiety from a variety of glycoconjugates and numerous natural glycosides. An α-l-rhamnosidase-secreting fungal strain was isolated from soil sample. Further, it was identified as Aspergillus flavus through internal transcribed spacer (ITS) gene sequencing. The enzyme was purified to homogeneity using ion-exchange and gel filtration chromatography and exhibited molecular weight of 71 ± 1 kDa. The maximum catalytic efficiency for the α-l-rhamnosidase was established to be pH 10.0 and at a temperature of 50°C. The purified enzyme exhibits a K<sub>m</sub> 0.41 ± 0.06 mM and a V<sub>max</sub> 2.43 ± 0.17 µmol/min/mg for naringin hydrolysis. In this study, we modeled the 3D structure of A. flavus α-l-rhamnosidase using SWISS Model and validated it via PDBsum and PROCHECK. Molecular docking of A. flavus α-l-rhamnosidase with naringin and p-nitrophenyl-α-l-rhamnopyranoside (pNPR) identified key binding interactions. Electrostatic surface analysis highlighted ligand-binding sites, revealing crucial residues for substrate recognition and enzyme stability. Active site residues of A. flavus α-l-rhamnosidase forming hydrogen bonds and hydrophobic interactions with naringin and pNPR were identified, providing insights into substrate specificity and its potential applications in glycoside hydrolysis.
Authors
- Vinita Yadav (ORCID: https://orcid.org/0000-0003-1026-5697)
- Donald R. Senger
- Pramod Kumar Yadav (ORCID: https://orcid.org/0000-0003-0026-1684)
- Soumen Barman (ORCID: https://orcid.org/0000-0002-7781-1974)
- Kunwar Vishal
Institutions
- Indian Institute of Science Education and Research Kolkata (IN)
- Chhatrapati Shahu Ji Maharaj University (IN)
Publication Details
- Journal
- Biotechnology and Applied Biochemistry
- Published
- 2025-09-21
- DOI
- https://doi.org/10.1002/bab.70053
- Primary Topic
- Phytochemical compounds biological activities
- Type
- article
- Field-Weighted Citation Impact
- 0.00