Michelle Frei

Catalytic pKa Attenuation in a Hydrolytic Metalloenzyme by Genetic Code Expansion Hydrolytic metalloenzymes employ Lewis-acidic metal cofactors to activate water molecules, generating nucleophilic hydroxide species that facilitate catalysis. Their catalytic efficiency across a wide...

Still obsessed with histidine (and its mimics)! Our latest work from Benjamin 🎉 uses genetic code expansion—tuning the primary coordination sphere of a dizinc metallohydrolase—lowering the catalytic pKa and boosting activity up to 5x at acidic pH. Check it out! doi.org/10.1021/acs.biochem.5c00768

🚨 Are you in need of a sensitive ratiometric protein kinase A (PKA) biosensor? 🚨 We got you covered: far-red, large changes, rapid response kinetics, selective! Anything you could wish for. Check out these two preprints from the Zhang Lab 🧪 🧑‍🔬
Congrats to everyone involved!

Gladys Mae West obituary: mathematician who pioneered GPS technology She made key contributions to US cold-war science despite facing huge barriers as a Black woman.

No joke: I got angry hate mail today for writing an obituary of a Black woman scientist—because the person felt she did didn’t deserve the recognition.

Which just makes me want to share it again: www.nature.com/articles/d41...

Biosensor types

🚨How do we implement synthetic fluorophores into biosensors? Have a look at Elias Dressler’s review article in Chimia. The issue highlights the work of Young Professors and Ambizione Fellows in Switzerland. Glad to be part of this vibrant community. ⚗️ www.chimia.ch/chimia/artic...

Synthetic fluorophores for live-cell fluorescence microscopy and biosensing - Nature Chemical Biology Performing live-cell microscopy experiments with high spatial and temporal resolution requires fluorophores with highly optimized properties. This Review examines the progress in developing synthetic ...

A new Review by Agnese Nicoli and Michelle Frei examines the progress in developing synthetic small-molecule fluorophores and how these in combination with innovative labeling strategies can advance chemical biology

www.nature.com/articles/s41...

Synthetic fluorophores for live-cell fluorescence microscopy and biosensing - Nature Chemical Biology Performing live-cell microscopy experiments with high spatial and temporal resolution requires fluorophores with highly optimized properties. This Review examines the progress in developing synthetic ...

🚨Curious how synthetic fluorophores simplify microscopy? Our review covers applications such as super-resolution microscopy and biosensing. 🎉👩‍🔬Congrats to my first PhD student, Agnese Nicoli, for the fearless deep dive! 🔬 ⚗️
D-CHAB @ethz.ch
www.nature.com/articles/s41...

Hijacking a bacterial ABC transporter for genetic code expansion - Nature Bacterial ATP-binding cassette (ABC) transporters can be utilized and engineered to transport non-canonical amino acids into Escherichia coli for highly efficient synthesis of proteins with novel func...

🚨Our paper is out! 🥳
Hijacking a bacterial ABC transporter for efficient genetic code expansion.
Many congrats to everyone involved - a multi-year effort led by @taruniype.bsky.social @maxfottner.bsky.social
www.nature.com/articles/s41...

it all started years ago with a failed experiment
🧵👇 1/9

#Mifobio2025

Focus on the module 1 :
👉 "Marking strategies at different scales of life"

We are delighted to welcome @michellefrei17.bsky.social
@ethz.ch

Lecture : "Chemigenetic kinase biosensors for multiplexed activity sensing and super-resolution imaging"

👉 imabio-cnrs.fr/mifobio-2025/

The 5th Virtual @chembiotalks.bsky.social on September 30th are one week away. We have an exciting program including our keynotes Sarah O'Connor (@oconnorlab.bsky.social) and @craigmcrews.bsky.social.

Make sure to register for free: web.cvent.com/event/...
#ChemSky #ChemBio

Good luck Wei🙂

This is a really, really important story, which is why I provided a gift link. Many people, when they think of higher education, think of elite universities. But most higher education is nonselective (i.e., they admit everyone), and a lot of it is community colleges.

🚨 2 × PhD positions @EPFL! 🚨
Help us push the boundaries of fluorescence microscopy - DNA nanotech, custom optics & spatial omics in Lausanne 🇨🇭. Start Jan 2026. Send CV + motivation + 2 refs → fschueder@ethz.ch
#PhD #Hiring #microscopy #SuperResolution #SpatialOmics #DNAPAINT #FLASHPAINT

💥 We have 3 positions open in my lab in Basel, Switzerland🇨🇭:
#nanopores #smFRET #biomolecular #dynamics #singleMolecules

We’re looking for talented & ambitious new colleagues enthusiastic about biomolecular dynamics & single-molecule tech.

Please share broadly, thank you!🤝

schmid.chemie.unibas.ch

We have multiple PhD and Postdoc positions open in my new group at Masaryk University. Are you an excellent and motivated candidate interested in organic and peptide synthesis and chemical biology? Get in touch! Start in January 2026. www.fialalab.com
Appreciate sharing!

Fast, Bright and Reversible Rhodamine Tags for Live-Cell Imaging We present Rho-tag and SiR-tag, engineered protein tags derived from bacterial multidrug-resistance proteins that bind unsubstituted (silicon-) rhodamines with nanomolar affinity, enabling fast, rever...

Teaching an old bacterial protein new tricks: Fast, bright and reversible rhodamine tags for live-cell imaging:

www.biorxiv.org/content/10.1...

Congratulations to Julian Kompa and the entire team.

SNAP-tag2 for faster and brighter protein labeling - Nature Chemical Biology SNAP-tag is a widespread tool for labeling protein for bioimaging. Now, Kühn et al. report SNAP-tag2 with increased labeling kinetics and brightness, which translates into a better performance in live...

📣Paper alert! Interested in faster and brighter protein labeling than before? 👀 @steffi-k.bsky.social & other colleagues have developed an improved tool for labeling proteins with synthetic fluorophores for bioimaging. Also works in STED microscopy 🤩🔬 Congratulations!🥳
www.nature.com/articles/s41...

Excited to be part of #SMLMS2025. Heard so many great things about this meeting in the past!

PhD Position in Peptide-Based Drug Discovery (Industry Collaboration, w/m/d)

We are hiring! Check out our open PhD position for an exciting industry collaboration with Novo Nordisk:
jobs.ethz.ch/job/view/JOP...

🔥 We've already received over a third of pre-registrations!

#Mifobio2025 is already shaping up to be a highly attractive event...

Don't delay in pre-registering!
👉 imabio-cnrs.fr

@cnrs.fr @cnrsbiologie.bsky.social @cnrsingenierie.bsky.social @cnrs-inist.bsky.social

Want to be part of the 5th Virtual ChemBio Talks? Submit you abstract until 📅 June 30th. Two amazing keynote speakers @oconnorlab.bsky.social and @craigmcrews.bsky.social are already confirmed. More coming soon. Stay tuned! ⚗️👩‍🔬🦠🧑‍🔬

And last but not least it was pleasure to work in @jinzhanglab.bsky.social and learn so much from Jin. Thanks for everything! #AmazingMentor

Big thanks also to all the collaborators at UCSD and USC: Longwei + Peter Wang, @faldalf.bsky.social + Scott Fraser, Zack, Hiro+ Joh Schöneberg, Yajuan + Lingyan Shi, and Theresa + Jerrold Olefsky.
Also grateful to @anne-lyons-bioe.bsky.social for all the help with super-res image analysis!

A special thanks goes to Sam, Xinchang, and Sohum at @jinzhanglab.bsky.social, who worked tirelessly to bring this one over the finish line!

Far-red chemigenetic kinase biosensors enable multiplexed and super-resolved imaging of signaling networks - Nature Biotechnology Far-red kinase biosensors are applied to image kinase signaling networks at super resolution.

Happy to see my Postdoc work out @natbiotech.nature.com. Using HaloTag and synthetic fluorophores instead of FPs enables us to shift the spectral properties of kinase activity reporters (KARs) to the far-red 🔬. Huge thanks to everyone involved @jinzhanglab.bsky.social!
www.nature.com/articles/s41...

Advertisement for PhD position

My lab at @ethzurich.bsky.social is looking for a motivated PhD student. We develop chemical tools for advanced fluorescence microscopy 🔬 and work at the interface of synthetic chemistry ⚗️ and protein engineering 🦠. Sharing with skilled Master students appreciated. More info at tinyurl.com/2dbjk5ty

We are happy to announce the new team that will organize the Virtual ChemBioTalks from this edition onwards
Marina Rubini
@mlakemeyer.bsky.social
@michellefrei17.bsky.social
Hana Macíčková Cahová
@drglycoben.bsky.social
@borisvauzeilles.bsky.social
@stephanhacker2.bsky.social
(1/4)
#ChemBio #ChemSky

🚨 PhD Opportunity!

Passionate about enzyme engineering or genetic code expansion? 🧬 Our lab is hiring a PhD student!

🔬 Exciting interdisciplinary research
🤝 Engaging environment 🌱

📄 Does this sound like you, apply now! ⏳🔗
📢 Know someone? Share this! 🔄

jobs.uzh.ch/job-vacancie...

The Frei Research Group is growing! Excited to see how the projects of Mario, Agnese, and Elias will develop in the next months and years. Also grateful for the amazing admin support by Karin. ⚗️🔬👩‍🔬👨‍🔬

Our lab has an open PhD student position in Protein Engineering - Neurotechnology. Apply if interested!

SiR-XActin: A fluorescent probe for imaging actin dynamics in live cells Imaging actin-dependent processes in live cells is important for understanding numerous biological processes. However, currently used natural-product based fluorescent probes for actin filaments affec...

Check out our new fluorescent probe for imaging f-actin dynamics: 𝗦𝗶𝗥-𝗫𝗔𝗰𝘁𝗶𝗻: 𝗔 𝗳𝗹𝘂𝗼𝗿𝗲𝘀𝗰𝗲𝗻𝘁 𝗽𝗿𝗼𝗯𝗲 𝗳𝗼𝗿 𝗶𝗺𝗮𝗴𝗶𝗻𝗴 𝗮𝗰𝘁𝗶𝗻 𝗱𝘆𝗻𝗮𝗺𝗶𝗰𝘀 𝗶𝗻 𝗹𝗶𝘃𝗲 𝗰𝗲𝗹𝗹𝘀 www.biorxiv.org/content/10.1...
Thank you @veselin-nasufovic.bsky.social