Australian Scorpion <i>Hormurus waigiensis</i> Venom Fractions Show Broad Bioactivity through Modulation of Bio-Impedance and Cytosolic Calcium
David M. Housley,
Jeremy L. Pinyon,
Georg von Jonquieres,
Chamini J. Perera,
Michael Smout,
Michael J. Liddell,
Ernest A. Jennings,
David Wilson,
Gary D. Housley
Affiliations
David M. Housley
Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, UNSW Sydney, Sydney, NSW 2052, Australia
Jeremy L. Pinyon
Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, UNSW Sydney, Sydney, NSW 2052, Australia
Georg von Jonquieres
Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, UNSW Sydney, Sydney, NSW 2052, Australia
Chamini J. Perera
Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, UNSW Sydney, Sydney, NSW 2052, Australia
Michael Smout
Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, QLD 4878, Australia
Michael J. Liddell
Centre for Tropical Environmental and Sustainability Science, College of Science & Engineering, Cairns Campus, James Cook University, Cairns, QLD 4878, Australia
Ernest A. Jennings
College of Medicine and Dentistry, Cairns Campus, James Cook University, Cairns, QLD 4878, Australia
David Wilson
Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, QLD 4878, Australia
Gary D. Housley
Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, UNSW Sydney, Sydney, NSW 2052, Australia
Scorpion venoms are a rich source of bioactive molecules, but characterisation of toxin peptides affecting cytosolic Ca2+, central to cell signalling and cell death, is limited. We undertook a functional screening of the venom of the Australian scorpion Hormurus waigiensis to determine the breadth of Ca2+ mobilisation. A human embryonic kidney (HEK293) cell line stably expressing the genetically encoded Ca2+ reporter GCaMP5G and the rabbit type 1 ryanodine receptor (RyR1) was developed as a biosensor. Size-exclusion Fast Protein Liquid Chromatography separated the venom into 53 fractions, constituting 12 chromatographic peaks. Liquid chromatography mass spectroscopy identified 182 distinct molecules with 3 to 63 components per peak. The molecular weights varied from 258 Da—13.6 kDa, with 53% under 1 kDa. The majority of the venom chromatographic peaks (tested as six venom pools) were found to reversibly modulate cell monolayer bioimpedance, detected using the xCELLigence platform (ACEA Biosciences). Confocal Ca2+ imaging showed 9/14 peak samples, with molecules spanning the molecular size range, increased cytosolic Ca2+ mobilization. H. waigiensis venom Ca2+ activity was correlated with changes in bio-impedance, reflecting multi-modal toxin actions on cell physiology across the venom proteome.
