10.1371/journal.pone.0191445.g007 Elodie Sanfins Elodie Sanfins Alexandra Correia Alexandra Correia Stefan B. Gunnarsson Stefan B. Gunnarsson Manuel Vilanova Manuel Vilanova Tommy Cedervall Tommy Cedervall Schematic representation of how MPO (green), particle surface and BSA (blue) concentration interplay to define the activity level of MPO. Public Library of Science 2018 nanoparticle concentration neutrophil degranulation environment myeloperoxidase activity 2018-01-18 18:49:34 Figure https://plos.figshare.com/articles/figure/Schematic_representation_of_how_MPO_green_particle_surface_and_BSA_blue_concentration_interplay_to_define_the_activity_level_of_MPO_/5800947 <p>(A) When purified MPO interacts with the particle surface its interaction modifies the conformation of the protein, which increase enzyme activity. (B) At medium protein concentration the MPO interaction with the surface is influenced by other proteins and is very active. (C) In high protein concentration media the MPO has less access to the surface and is less active either because of less MPO is bound to the surface or that the conformational change is less favorable in a crowded environment.</p>