Monday, 6 September 4:00pm – 4:30pm

This seminar will be delivered via Zoom – Please email chemistry.researchsupport@sydney.edu.au for zoom link and password.

Speaker: Jianping Zhu

Host: Professor Elizabeth New

Title: Fluorescent probes for metals in biology

Abstract: Metals, which occupy 80% of the periodic table, play significant roles in biology. Many transition metals are essential for living organisms as molecular transporters, catalysts and modulators of metabolism. Toxic metals, even in trace concentrations, induce adverse effects to biological systems. Understanding how metals function in living organisms facilitates disease diagnosis and therapy, which inspires the development of tools for studying metals in biology. Fluorescent probes have been shown to operate as effective tools in biological studies, providing both high resolution and dynamic information for metals of interest.

In this talk, I will present the development of fluorescent probes for lead, copper and for uncovering metal interactions with lipid droplets. RPb1 is a rhodamine-based fluorescent probe for lead that has been applied to study the cellular labile lead pool.¹ Complementary techniques such as flow cytometry studies using RPb1, ICP-MS and single cell ICP-MS were used to study labile and protein-bound lead within K562 cells. CyCu1 is a cyanine-based NIR probe for Cu(II). CyCu1 exhibits both fluorescence and absorption changes in response to Cu(II) with high selectivity, enabling fluorescent / photoacoustic dual-modality in vivo imaging of Cu(II) in neuroblastoma and Parkinson’s disease model.

Finally, little is known about the interactions of metals with lipid droplets, and in order to address this challenge it is important to have robust markers of these important organelles. BoL1 and BoL2 are BODIPY-derived probes that are able to label lipid droplets in cells. Strong fluorescence emission and good photostability of BoL1 and BoL2 allow them to be used for lipid droplets imaging on STED and dSTORM super-resolution microscopy. BoL2 was applied to track the exchange of lipid droplets between different cells. BoL1 and BoL2 provide robust fluorescent scaffolds for the development of probes that can explore metals within lipid droplets in the future.

Reference:

¹ Jianping Zhu, Jia Hao Yeo, Amy A. Bowyer, Nicholas Proschogo and Elizabeth J. New, Studies of cellular lead uptake using a rhodamine-based fluorescent probe, Metallomics, 2020, 12, 644-648.