title: Permeability effects on the efficiency of antioxidant nanoreactors.
abstract: Enzyme-loaded polymeric vesicles, or polymersomes, can be regarded as nanoreactors, which, for example, can be applied as artificial organelles. We implemented a naturally occurring enzymatic cascade reaction in two types of polymersomes, which are known to possess different permeability properties. The selected cascade reaction involved the antioxidant enzymes superoxide dismutase (SOD1) and catalase (CAT) for combating oxidative stress. The activities of both enzymes were investigated by spectrophotometric and electrochemical assays. Whereas the SOD1 substrate (the radical anion superoxide, O2•-) was able to penetrate both membranes equally well, the CAT substrate (H2O2) showed different rates of diffusion. When O2•- was generated inside polymersomes filled with both SOD1 and CAT, the activities of the two systems were comparable again.
authors.affiliation: Radboud University Nijmegen, Institute for Molecules and Materials, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands.
authors.forename: Iria
authors.initials: I
authors.lastname: Louzao
authors.forename: Jan C M
authors.initials: JC
authors.lastname: van Hest
mesh_terms: D000975:Antioxidants / Q000378:metabolism*; D058045:Artificial Cells / Q000378:metabolism*; D001692:Biological Transport; D019149:Bioreactors; D002374:Catalase / Q000737:chemistry / Q000378:metabolism*; D002462:Cell Membrane; D057075:Enzyme Assays; D018384:Oxidative Stress; D010100:Oxygen / Q000737:chemistry / Q000378:metabolism; D010539:Permeability; D011108:Polymers / Q000737:chemistry; D017382:Reactive Oxygen Species / Q000378:metabolism; D013482:Superoxide Dismutase / Q000737:chemistry / Q000378:metabolism*; D000072105:Superoxide Dismutase-1; D013481:Superoxides
chemical_list: D000975:Antioxidants; D011108:Polymers; D017382:Reactive Oxygen Species; D013481:Superoxides; D002374:Catalase; D013482:Superoxide Dismutase; D000072105:Superoxide Dismutase-1; D010100:Oxygen