Chemical Probes for GPCR Imaging and Internalization with Dr. Johannes Broichhagen

In this episode of The Dr. GPCR Podcast, chemical biologist Dr. Johannes Broichhagen shares how his lab builds next-generation fluorescent probes to visualize GPCRs with precision. From the early days of ion channel chemistry to pioneering peptide–fluorophore conjugates for the GLP-1 receptor, JB breaks down the strategic decisions that shaped these tools—and why reliable chemical probes are transforming GPCR drug discovery.

He explains what chemical design can solve that antibodies can’t, how to validate functional assay systems, and why fluorescence-based assays paired with careful synthetic planning open doors for both high-resolution imaging and high-throughput screening.

You will walk away with a deeper understanding of GPCR internalization, probe specificity, and the cross-disciplinary habits that make collaborations actually work.

Why this matters

How a chemist with zero biology training became a leader in GPCR probe design.
Why peptide-based fluorescent ligands succeeded where antibodies repeatedly failed.
What actually happened the moment JB and collaborators imaged an entire pancreatic islet in one shot.
How parallel synthesis and side-by-side functional assays accelerate probe optimization and reduce false leads.
Why targeting the pharmacologically relevant surface-exposed receptor pool changes the way scientists interpret GPCR trafficking.
The moment when super-resolution imaging revealed nanoscale receptor domains that conventional tools completely missed.

Who should listen

If you’ve ever:

Navigated a project where the biology refused to match the textbook mechanism.
Balanced creativity in tool development with the pressure for reproducible, publication-grade data.
Tried to build assays that behave in living cells—not just on paper.
Collaborated across chemistry and biology and felt the translation gap firsthand…

…this episode will resonate.

About Johannes Broichhagen

Dr. Johannes Broichhagen is a chemical biologist whose work sits at the intersection of organic synthesis, peptide chemistry, and advanced imaging. Born in 1984, he studied chemistry at the University of Erlangen-Nuremberg (2004–2010) and completed his doctorate at LMU Munich in 2014 .

His postdoctoral training included research at the École Polytechnique Fédérale de Lausanne (2015–2016) and later at the Max Planck Institute for Medical Research in Heidelberg, where he served as both postdoc and departmental group leader (2017–2020). These years shaped his interest in ion channels, GPCR pharmacology, and the chemical strategies needed to probe complex biology.

Since 2020, JB has led his research group at the Leibniz Research Institute for Molecular Pharmacology (FMP) in Berlin, focusing on developing fluorescent chemical tools to visualize GPCRs and other cell-surface proteins with high specificity. His lab integrates synthetic chemistry, theoretical chemistry, cell biology, and imaging to understand receptor organization and dynamics across cells, tissues, and intact organisms.

Curiosity, collaboration, and a love of translating chemical concepts into biological insight drive his scientific mission.