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Posts by Katrin_Ackermann

Beyond a Passive Tether: Structural Insights into the Disordered Tail of Hsp90 The molecular chaperone Hsp90 is an abundant and essential homodimer that supports the stability and folding of hundreds of client proteins in cells. Its C-terminal domain (CTD) mediates dimerization and serves as a docking site for cochaperones bearing tetratricopeptide repeat (TPR) domains, which recognize the conserved MEEVD motif located at the end of an intrinsically disordered CTD tail. Despite its conservation, the structural role of this tail remains poorly understood. We investigated the conformational behavior of the yeast Hsp90 (yHsp90) CTD tail and its response to the binding of the TPR-containing PPIase cochaperone Cpr6. Using site-directed spin labeling with nitroxide and Gd(III) labels, we examined full-length yHsp90 (FL), isolated CTD (IsoC), and tail-truncated variants by double electron–electron resonance (DEER) and EPR spectroscopy. The CTD tails in IsoC and FL adopted distinct conformational ensembles, attributed to intramolecular interactions with the middle domain in FL. Cpr6 binding abolished these differences, indicating disruption of intramolecular tail contacts. In IsoC, the tail also stabilized an additional CTD conformation near the dimer interface that was absent in FL and was lost upon tail truncation, consistent with tail–CTD interactions observed by NMR. This population was reduced upon Cpr6 binding, shifting the IsoC conformational distribution toward that of FL. Additionally, this population was reduced in cellular environments and mimics. Together, our results demonstrate that the disordered CTD tail is an active structural element that modulates both its own conformational ensemble and CTD architecture, highlighting its potential functional relevance in the Hsp90 chaperone cycle.

✨ New paper out in #JACS! We looked at the intrinsically disordered CTD tail of #Hsp90 often seen as a passive linker. Turns out, it’s not.
#StructuralBiology #Biophysics #EPR #NMR
pubs.acs.org/doi/10.1021/...

1 week ago 4 4 0 0
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Crystallographic and EPR-based characterisation of Cu2+-binding to serum albumin: ATCUN coordination and additional sites Copper homeostasis is essential for mammalian physiology. Serum albumin plays an important role in plasma copper transport and buffering, yet its Cu2+ binding sites have remained incompletely characte...

Just published: copper(II) binding to Human Serum Albumin. 1st structure including the ATCUN site that is square planar as expected. There are multiple copper(II) sites and EPR (including hyperfine and pulse dipolar) reveals occupation of multiple sites at low loading. doi.org/10.1039/D6QI...

1 month ago 15 3 1 0
Swapped and non-swapped TRAAK states co-exist in membranes at a ratio influenced by temperature Nature Communications - TRAAK is expressed in the nervous system and helps regulate neuronal excitability. Here, the authors use EPR to quantify the relative populations of TRAAK’s swapped...

Work just published in @natcomms.nature.com rdcu.be/e9ieD demonstrating how pulse dipolar EPR can resolve different states of a human transporter in native membranes. EPR contributions by @ackermannkatrin.bsky.social @st-andrewschem.bsky.social

1 month ago 4 3 1 0
A photo from a train in Scotland of a door saying "Stay out. Bagpipe practice."

A photo from a train in Scotland of a door saying "Stay out. Bagpipe practice."

Signs you're on Scottish train...

1 month ago 149 33 1 0
Swapped and non-swapped TRAAK states co-exist in membranes at a ratio influenced by temperature - Nature Communications TRAAK is expressed in the nervous system and helps regulate neuronal excitability. Here, the authors use EPR to quantify the relative populations of TRAAK’s swapped and non-swapped cap states in membr...

In our study in @natcomms.nature.com we used #EPR #DEER #PELDOR spectroscopy with single subunit heterologous spin labelling and monitored the entire cap conformational ensemble of the human mechanosensitive TRAAK channel and showed it adopts two states in membranes.

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

1 month ago 8 5 1 1
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Structural characterization and the role of EPR spectroscopy for protein–polymer conjugates Protein-polymer conjugates (PPCs) are an important class of therapeutic macromolecules offering improvements in protein stability, circulation time, a…

Protein–polymer conjugates: how do we understand their structure & dynamics? 🔬Our new review highlights EPR spectroscopy+complementary techniques for insights in vitro & in cells.
Read more 👇
www.sciencedirect.com/science/arti...
#ProteinPolymerConjugates #EPR #Biomaterials #PolymerScience

1 month ago 6 4 0 0

Our latest CRISPR ring nuclease paper focusses on Csx15 - which seems to act as of a sponge as well as a canonical phosphodiesterase. Great work led by @haotianchi.bsky.social

www.biorxiv.org/content/10.6...

2 months ago 36 20 0 0
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Officially inducted as Professor of the University of St Andrews today. @uniofstandrews.bsky.social @st-andrewschem.bsky.social This would not have been possible without the contributions co-workers and collaborators past and present. Many thanks to you all.

4 months ago 14 4 5 1

Many congratulations Nino! 👏🎉👏

5 months ago 1 0 0 0
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Careers

Bruker Corporation | Career | EPR Application Scientist (m/f/d) in Ettlingen, Baden-Württemberg | Careers at DE, Ettlingen

germancareers-bruker.icims.com/jobs/18525/e...

6 months ago 2 2 0 0
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Fantastic news! 🎉 Our University is ranked #2 in the UK in both the Guardian University Guide 2026 and Times & Sunday Times Good University Guide 2026. Special congratulations to Chemistry – #1 in the UK (Times) and #2 (Guardian)! 👏👏

6 months ago 3 1 0 0
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Chiral molecular 4f qubits by post functionalization We herein demonstrate the synthesis of a pair of enantiomerically pure YbIII complexes by post-functionalisation of the parent YbIII complex via condensation with an enantiomerically pure chiral amine...

A new paper 📜 with the Piligkos Lab at DTUpublished in ‪@inorgchemfront.rsc.org‬ We show that Chiral molecular 4f qubits retain properties suitable for quantum information processing. Thanks to all involved. ⚛️ 🧪 doi.org/10.1039/D5QI...

7 months ago 4 3 0 1
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Toward Generalized Solution-State 1H DNP NMR via Particle-Mediated Cross-Relaxation This study discusses a potential route for enhancing 1H NMR signals in the liquid phase at high magnetic fields for samples on the 100 μL volume scale using dynamic nuclear polarization (DNP). The approach involves dispersing an inert powder that is both rich in protons and capable of undergoing DNP with good efficiency at noncryogenic temperatures, and letting the solid 1H polarization thus enhanced pass from the dispersed particles onto the surrounding liquid via spontaneous cross relaxation effects. To this end, BDPA-doped polystyrene (PS) particles in the μm range were suspended in 30 μL of heptane, loaded into 3.2 mm sapphire rotors, and spun at ≈500 Hz for homogeneity purposes in a 14.1 T magnet. Irradiation with ≈13 W at 395 GHz while maintaining temperature in the 185–220 K range thus enhanced the PS proton polarization ≈12-fold within ≈2 s; after ca. 6 s of irradiation, this resulted in ca. 3-fold enhancements of the heptane proton resonances, while preserving their ≤2 Hz line widths. The conditions over which such particle-mediated transfer occurs were explored over a range of sample composition, deuteration and molecular weight; best results were obtained when polarizing a ball-milled powder made of deuterated-PS/PS/BDPA = 86.4/9.6/4.0 suspended on perdeuterated heptane-d16. While the solution-state enhancements provided by this approach are still relatively modest, its generality could open new avenues in DNP-enhanced 1H NMR that do not sacrifice on the volumes, on the high-resolution conditions, or on the multiscan averaging that is customary in contemporary applications.

New paper out in J. Phys. Chem. Lett.: Toward Generalized Solution-State ¹H DNP NMR.
BDPA-polystyrene boosts ¹H ~12× in 2s, transfers ~3× to liquids in 6s
🔗 pubs.acs.org/doi/full/10....
#NMR #DNP #Hyperpolarization

7 months ago 4 3 0 1

🤣 They have never ever got my name correct. If I make up a name they take so long I have forgotten by the time the drink is ready. The only solution is to avoid them altogether...

10 months ago 4 1 0 0

Many thanks Dongmei, Alan, and @belab.bsky.social !

1 year ago 1 0 0 0
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Happy International Women's Day 2025!
So happy to have contributed an article in
@daltontrans.rsc.org for their Themed Collection:
doi.org/10.1039/D4DT...
#EPR #ESR @st-andrewschem.bsky.social

1 year ago 5 4 1 0
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Last paper of 2024. A combination of ENDOR and PELDOR pulse EPR methods to investigate preorganisation and conformational flexibility in a fluoride sensing riboswitch.
@st-andrewschem.bsky.social @ackermannkatrin.bsky.social @angewandtechemie.bsky.social

1 year ago 3 3 0 0
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Broad substrate scope C-C oxidation in cyclodipeptides catalysed by a flavin-dependent filament - Nature Communications Cyclodipeptide oxidases are filamentous enzymes. Here, the authors dissect the mechanism of a promiscuous flavoenzyme from the biosynthesis of cyclodipeptide natural products, unveiling fast catalysis...

The 2nd paper of 2025 with some #EPR contribution of us showing a radical in the cyclodipeptide oxidase reaction that is dependent on substrate.
doi.org/10.1038/s414...

@ackermannkatrin.bsky.social
@st-andrewschem.bsky.social

1 year ago 5 4 0 0
conference poster

conference poster

the 58th Annual International Meeting of the RSC ESR spectroscopy group at University College London, 1st to 5th June, 2025 www.esr-group.org/conferences/... #NMRchat #NMR #ESR #EPR 🧲

1 year ago 2 1 0 0
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This cartoon is from 1930.

It could have been today.

1 year ago 7941 2732 137 109

Hello world

I am an #EPR spectroscopist interested in biophysical chemistry and catalysis.

I signed up here some time ago but now I stopped using the other place.

I could not bear the landlord anymore.🐦

1 year ago 8 4 0 0
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Lecturer in Organic Chemistry - AC2577LS at University of St Andrews An academic position as a Lecturer in Organic Chemistry - AC2577LS is being advertised on jobs.ac.uk. Click now to find more details and explore additional academic job opportunities.

@uniofstandrews.bsky.social looking to hire a lecturer in organic chemistry. A fantastic place to work with wonderful students and colleagues. www.jobs.ac.uk/job/DKW116/l... 🧪 ⚗️ #chemsky

1 year ago 11 14 0 1
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University of Reading proposes closing its chemistry department next year The university joins several others that are considering the future of their departments and undergraduate programmes

Chemistry degrees have some of the highest values of any degree and are vital if we want to build a competitive high-tech nation. But they are expensive, and so if universities want to save money quickly they will just ignore national priorities and close them.
www.chemistryworld.com/news/univers...

1 year ago 210 92 20 17

Hello Bsky - just migrated here.

Little introduction:
Biochemist, working on biomolecular applications of #EPR #ESR, senior research fellow in Chemistry at St Andrews University, Scotland.
Enjoy things like long walks along the beach and some good food afterwards.

1 year ago 10 3 0 0