Brian Cook

1) The Herzik lab is excited to announce our newest preprint in collaboration with the Grotjahn lab! We have developed a surfactant cocktail that seeks to overcome one of the more nefarious problems in #cryoEM, Air-water interface (AWI)-induced damage and preferred orientation (PO).

Brian Cook reposted

Edward T Eng

@edwardteng.bsky.social

10 June

The next #CryoEM Current Practices Webinar speaker will be Mark Herzik from UCSD speaking on "Old tools, new tricks: engineering better cryoEM sample preparation workflows through design and chemistry" 6/25/2026 at 12 PM ET / 9AM PT Register here : us02web.zoom.us/webinar/regi...

8) While we explore SurfACT in our preprint: tinyurl.com/SurfACT-prep..., we show that this cocktail can be a generalizable solution to enable many difficult proteins adopt more ideal behaviors during freezing.

9) This was a fantastic team effort led by Suzanne Enos with a fun and insightful collaboration between the Herzik lab at @ucsandiego.bsky.social and Grotjahn lab at @scripps.edu. #cryoET #cryoEM #HerzikLab @sptlabtech.bsky.social @structurabio.bsky.social @thermofishersci.bsky.social

6) Importantly, we demonstrate that SurfACT can be used with any of your favorite grid prep devices! SPT Labtech chameleon ✅ TFS Vitrobot ✅ Custom manually-operated plunger ✅.

7) Using cryoET and STA we find that aldolase particles stuck at the AWI not only adopt a single orientation, but these particles are also partially denatured at the AWI! Only when aldolase particles were pushed into bulk ice with SurfACT did they remain intact.

4) We teamed up with @nanigrotjahn.bsky.social and @hamid13r.bsky.social to do a through examination of SurfACT with four known proteins that suffer from PO. Combining #SPA and #cryoET paired with #STA, we show that SurfACT overcomes PO for these proteins and provides insights into this problem.

5) We first sought to test SurfACT with a pathologically preferred specimen, hemagglutinin. We find that without SurfACT, the particles adopt a “top-down” view and the density is incomplete. Addition of SurfACT drastically reduces PO, flipping particles and leading to a complete ~2.1 Å density.

2) ) PO, where particles adopt non-random orientations at the AWI, is a leading causes of failure in single-particle cryoEM. We rationally designed a cocktail of four synergistic surfactants that disrupt particle interactions with the AWI to improve reconstruction quality and particle integrity.

go.nature.comStructural basis for the conformational protection of nitrogenase from O2 - NatureCryo-electron microscopy of Azotobacter vinelandii FeSII–nitrogenase reveals a core complex of molybdenum–iron proteins (MoFePs), iron proteins (FePs) and FeSII, in which FeSII mediates interactions with MoFeP and FeP to position their FeS clusters in catalytically inactive but O2-protected states.

3) Our surfactant cocktail, SurfACT, is designed with minimal sample-dependent screening in mind and can be used across protein classes and EM sample preparation devices.

Brian Cook reposted

Ben Barad

@baradlab.com

7 Mar 2025

Happy to share that the final version of record for our ( @nanigrotjahn.bsky.social) #teamtomo mitochondrial cotranslation story is online at @jcb.org! We combined STA with surface morphometrics to learn how ribosomes bind to and alter mitochondrial membranes in yeast. rupress.org/jcb/article/...

Brian Cook reposted

Nature

@nature.com

13 Jan 2025

Nature research paper: Structural basis for the conformational protection of nitrogenase from O2 https://go.nature.com/4aiD344

Brian Cook reposted

Ray Berkeley

@ray-berkeley.bsky.social

9 Jan 2025

Awesome work from Sarah, @bcryo.bsky.social and friends in the Herzik Lab! It was cool to see this come together in such a short time.

Brian Cook@bcryo.bsky.social

1) Since I am the only Herzik lab member on @bsky.app, I get the privilege to announce our most recent publication from the Herzik/Tezcan labs. I got the wonderful opportunity to contribute on the cryoEM study of the oxygen protection mechansim employed by cells to protect Nitrogenase!

7) This was an exciting study led by Sarah Narehood in collaboration with Suppachai Srisantitham, Vanessa Eng, Angela Shiau, Kelly McGuire, David Britt. #cryoEM #cryoSPARC #Nitrogenase #HerizkLab @nature.com @sptlabtech.bsky.social @structurabio.bsky.social #UCSDChemBioChem #anaerobicEM

nature.comStructural basis for the conformational protection of nitrogenase from O2 - NatureCryo-electron microscopy of Azotobacter vinelandii FeSII–nitrogenase reveals a core complex of molybdenum–iron proteins (MoFePs), iron proteins (FePs) and FeSII, in which FeSII mediates interactions w...

8 Jan 2025

The paper can be found here: www.nature.com/articles/s41...

5) Our structures combined with our analytical ultracentrifugation and EPR experiments allow us to propose a mechanism by which these oxygen protecting complexes and filaments form in oxidizing conditions, protecting MoFeP and FeP, and disassemble in reducing conditions.

8 Jan 2025

6) We were able to achieve these structures using our newly developed (an)aerobic freezing protocol using the SPT chameleon. This allowed us to generate high quality girds with thin ice without having to be in an anaerobic chamber! www.biorxiv.org/content/10.1...

3) We show that Shetna is capable of binding both the catalytic (MoFeP) and reductant (FeP) subunits, creating oxygen protecting complex. Fascinatingly, this complex is capable of forming higher order complexes and ultimately filaments!