Encapsulation in a Bacterial Microcompartment Shell Improves Thermal Stability of a Glycolytic Enzyme

Area of Science:

• Biotechnology
• Protein Engineering
• Synthetic Biology

Background:

• Bacteria utilize bacterial microcompartments (BMCs) for enzyme encapsulation to enhance catalysis and manage metabolic intermediates.
• The Haliangium ochraceum (HO) BMC shell is a versatile chassis for enzyme encapsulation due to its modularity and ease of expression.
• Previous work demonstrated in vivo assembly of HO-BMCs with triose phosphate isomerase (TPI).

Purpose of the Study:

• To demonstrate the advantages of in vitro assembly (IVA) for targeted enzyme encapsulation using the HO BMC system.
• To achieve variable loading of BMC shells with specific amounts of TPI cargo.
• To assess the impact of encapsulation on TPI's thermal stability.

Main Methods:

• Utilized in vitro assembly (IVA) techniques to construct HO BMC shells.
• Incorporated triose phosphate isomerase (TPI) as a model enzyme cargo.
• Quantified enzyme loading and measured the thermal stability of encapsulated versus free TPI.

Main Results:

• Successfully achieved variable loading of HO BMC shells with targeted amounts of TPI.
• Demonstrated enhanced thermal stability for encapsulated TPI compared to free TPI.
• Encapsulated TPI maintained stability up to 62 °C.

Conclusions:

• In vitro assembly provides a controllable method for targeted enzyme encapsulation within HO BMCs.
• Enzyme encapsulation significantly enhances thermal stability, a key advantage for biotechnological applications.
• The HO BMC system is a promising platform for developing robust biocatalysts.