Purification, characterization, and structural insights of Exo-1,4-β-D-glucosaminidase from Amycolatopsis sp. KLSc63: predictive modeling with glucosamine and N-acetyl glucosamine dimers.

Chitin, a long-chain polysaccharide, is a major component in the exoskeletons of arthropods and the cell walls of fungi. Its derivative, chitosan, is widely used in various fields due to its solubility and versatility. This study focuses on the purification and biochemical characterization of exo-1,4-β-D-glucosaminidase from Amycolatopsis sp. KLSc63, an enzyme crucial for the degradation of chitin and chitosan. The enzyme was purified using anion exchange chromatography and characterized for its activity on colloidal chitin and chitosan solutions. Optimal activity was observed at pH 5.0 and temperatures of 40-45 °C for colloidal chitin and pH 4.0-6.0 at 55 °C for chitosan solution. The enzyme's molecular weight was approximately 94 kDa. Various metal ions and surfactants significantly influenced enzyme activity, with Mn²⁺ at 1 mM concentration notably enhancing both activities. Structural modeling and docking studies confirmed the enzyme's substrate specificity and binding interactions. These findings highlight the potential applications of exo-1,4-β-D-glucosaminidase in industrial processes, waste management, and the production of bioactive compounds.