Computer-Based Design to Improve Bacillus thuringiensis Chitinase for Industrial Applications.

Area of Science:

• Biotechnology
• Enzyme Engineering
• Biopolymer Chemistry

Background:

• Chitin is a key biopolymer derived from seashell waste.
• Enzymatic bioconversion using chitinase is an eco-friendly extraction method.
• Limited strategies exist to improve chitinase catalytic performance.

Purpose of the Study:

• To enhance chitinase activity and stability using in silico site-directed mutagenesis.
• To identify specific mutations that improve substrate affinity and catalytic efficiency.
• To explore computational approaches for rational enzyme engineering.

Main Methods:

• In silico site-directed mutagenesis was performed on the chitinase catalytic domain.
• High mutability scores and functional relevance guided mutation site selection.
• Molecular orbital analysis and interaction analyses were used to evaluate mutant properties.

Main Results:

• Six hotspot mutations (V215A, V215F, S262G, R264H, F288L, G291A) were identified.
• Beneficial mutants showed increased substrate affinity compared to the native enzyme.
• The G291A mutant exhibited a reduced activation energy (49.53 kcal/mol vs. 97 kcal/mol), indicating enhanced catalytic efficiency.

Conclusions:

• Computationally guided mutagenesis is a viable strategy for optimizing chitinase.
• The G291A mutation significantly improves chitinase catalytic performance.
• This research advances enzyme engineering for industrial bioconversion applications.