Effects of Polypropylene and Polyethylene Terephthalate Microplastics on Trypsin Structure and Function

Area of Science:

• Environmental Science
• Biochemistry
• Food Science

Background:

• Microplastic (MP) ingestion is a significant exposure route for humans and animals.
• MPs interact with gastrointestinal enzymes and food proteins during digestion.

Purpose of the Study:

• Investigate trypsin adsorption onto polypropylene (PP) and polyethylene terephthalate (PET) MPs.
• Assess MP influence on trypsin structure and activity.
• Evaluate in vitro trypsin digestibility of bovine meat extract (BME) proteins and allergens in the presence of MPs.

Main Methods:

• Studied protein corona formation (soft and hard) on MPs.
• Analyzed trypsin adsorption, structural changes, and activity loss.
• Assessed protein and allergen digestibility using in vitro assays.

Main Results:

• Trypsin, BME proteins, and allergens formed dynamic coronas on MPs.
• Trypsin in the hard corona lost significant activity; slight structural changes occurred elsewhere.
• MPs slightly slowed the digestion of 38 kDa proteins but did not affect α-Gal-carrying allergens.

Conclusions:

• Realistic MP concentrations in the intestine are unlikely to significantly affect meat protein or allergen digestibility by trypsin.
• The protein corona on MPs consists of BME sarcoplasmic and allergenic proteins.