Mircoplastics (MPs) are an abundant contaminant in the environment with ingestion being
the most common way of exposure for humans. Binding of protein to MPs is proposed to
be multilayered with the formation of a soft and hard corona1. It has been proven that MPs
interact with enzymes present in the digestive system and impact their activity2. The aim of
this study is to investigate the impact of MPs on the activity of trypsin in simulated
intestinal fluid (SIF). For this purpose, two sizes of polypropylene (large – 180-500 μm,
small – 63-180 μm) and one size of polyethylene terephthalate (<80 μm) have been
studied. Activity in bulk and soft corona was determined in SIF at 405 nm with Nα-Benzoyl-DL-arginine 4-nitroanilide hydrochloride after different times of incubation.
Activity in hard corona was determined after 1 h of incubation with the MPs. Although
specific activity in the control decreases through time, there is a tendency for all MPs to
preserve activity in bulk and soft corona trypsin after 4 h of incubation. Trypsin remains
active in the hard corona, with the activity being an order of magnitude lower than in the
control, possibly due to significant changes in structure.
Acknowledgements
This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 965173.
References
1. Monopoli MP, Åberg C, Salvati A, Dawson, KA. Biomolecular coronas provide the biological identity of nanosized materials. Nat Nanotechnol 2012;7:779-86.
2. de Guzman MK, et al. Small polystyrene microplastics interfere with the breakdown of milk proteins during static in vitro simulated human gastric digestion. Environ Pollut 2023;335:122282
