Abstract
Magnetotactic bacteria synthesize magnetic particles called magnetosomes that cause them to orient to their external magnetic fields. However, the physiological significance and other possible functions of these magnetosomes have not been explored in detail. In this study, we have investigated the biological functions of magnetosomes with respect to their ability to scavenge reactive oxygen species (ROS) in Magnetospirillum gryphiswaldense MSR-1. To assess the changes in ROS levels under different conditions, cells were cultured under aerobic or micro-aerobic conditions in medium containing high and low amounts of iron. To ensure that the observed results were not due to nonspecific interactions, reactions were carried out using a mutant deficient in synthesizing magnetite (mamO-deficient mutant), its complementary strain or the wild-type MSR-1. We observed that the levels of intercellular ROS under micro-aerobic conditions with high-iron medium were much higher when the non-synthetic Fe(3) O(4) crystals mutant Mu21-415 was employed for the assay, compared with the wild-type or complementary strain, or when conditions were aerobic with low-iron medium. These results indicated that magnetosomes function in the scavenging of intracellular ROS. Furthermore, we have demonstrated that the magnetosomes exhibit peroxidase-like properties, by using the earlier reported in vitro horseradish peroxidase assay for artificial magnetic nanoparticles. In addition to possessing peroxidase-like activity, the magnetosomes also exhibited a more enzymatic kinetic response, suggesting that proteins on the membranes of the magnetosomes likely contribute to the enzymatic activity. This is the first study to demonstrate that magnetosomes play an important role in decreasing or eliminating ROS.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.