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Brian Cook

@bcryo.bsky.social

214 followers 477 following 21 posts

CryoEM PostDoc in Mark Herzik's lab at UCSD

Posts Replies Media

Brian Cook @bcryo.bsky.social · 23/03/2026

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.

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Brian Cook @bcryo.bsky.social · 23/03/2026

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.

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Brian Cook @bcryo.bsky.social · 23/03/2026

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 ✅.

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Brian Cook @bcryo.bsky.social · 23/03/2026

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.

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Brian Cook @bcryo.bsky.social · 23/03/2026

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).

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Brian Cook @bcryo.bsky.social · 08/01/2025

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...

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Brian Cook @bcryo.bsky.social · 08/01/2025

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.

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Brian Cook @bcryo.bsky.social · 08/01/2025

4) Surprisingly, the binding of Shethna occurs at the catalytic interface of both MoFeP and FeP! Preventing nitrogen fixation while also protecting the oxygen sensitive metal clusters harbored by both MoFeP and FeP.

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Brian Cook @bcryo.bsky.social · 08/01/2025

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!

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Brian Cook @bcryo.bsky.social · 08/01/2025

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!

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