Abstract
β-Neurotoxins are secreted phospholipase A2 molecules that inhibit transmission in neuromuscular synapses by poisoning the motor neurons. These toxins specifically and rapidly internalise into the nerve endings of motor neurons. Ammodytoxin (Atx) is a prototype β-neurotoxin from the venom of the nose-horned viper (Vipera ammodytes ammodytes). Here, we studied the relevance of the enzymatic activity of Atx in cell internalisation and subsequent intracellular movement using transmission electron microscopy (TEM). We prepared a recombinant, enzymatically inactive mutant of Atx, Atx(D49S), labelled with gold nanoparticles (GNP), and incubated this with PC12 cells, to analyse its localisation by TEM. Atx(D49S)-GNP internalised into the cells. Inside the cells, Atx(D49S)-GNP was detected in different vesicle-like structures, cytosol, endoplasmic reticulum and mitochondria, where it was spotted in the intermembrane space and matrix. Co-localization of fluorescently labelled Atx(D49S) with mitochondria in PC12 cells by confocal fluorescence microscopy confirmed the reliability of results generated using Atx(D49S)-GNP and TEM and allowed us to conclude that the phospholipase activity of Atx is not obligatory for its cell internalisation and translocation into the mitochondrial intermembrane space and matrix.
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.