An engineered platform based on chitin-affinity immobilization for producing low molecular weight heparin

Area of Science:

• Biotechnology
• Biochemistry
• Materials Science

Background:

• Heparinase I (Hep I) enzyme's interaction with chitin can be leveraged for biotechnological applications.
• Controlled production of low molecular weight heparin (LMWH) is crucial for therapeutic applications.
• Enzyme immobilization enhances stability and reusability, improving process economics.

Purpose of the Study:

• To develop an engineered platform for controllable LMWH production using chitin-affinity interaction.
• To immobilize and enhance the stability and reusability of triple-functional heparinase I (Hep I).
• To achieve efficient and purified LMWH fractions through a bioinspired approach.

Main Methods:

• Fabrication of chitin microspheres with nanofibrils via a "bottom up" approach.
• Expression of an enhanced soluble protein, ChBD-SUMO-Hep I (CSH-I), in batch fermentation.
• Immobilization of CSH-I onto chitin microspheres via chitin binding domain (ChBD) interaction.
• Enzymatic degradation of heparin monitored by absorbance at 232nm.

Main Results:

• High bioactivity of CSH-I (2.5×10³ IU/L) achieved through fermentation.
• Immobilized CSH-I exhibited superior tolerance to heat and pH, and improved shelf-life compared to free enzyme.
• The immobilized enzyme was reused up to 8 times with a conversion yield exceeding 90%.
• Qualified LMWH fractions were successfully obtained.

Conclusions:

• The engineered chitin-affinity platform enables efficient and controllable production of LMWH.
• Enzyme immobilization on chitin microspheres significantly enhances enzyme stability, reusability, and process efficiency.
• This bioinspired approach offers a promising strategy for scalable and cost-effective LMWH manufacturing.