Not wizard stuff but i recently saw someone with 19F NMR license plate and was pretty jealous of their chemistry vanity plate.

I think they just took awhile to listen to you...

Congrats well deserved !

there were two institutions that each had 23% of all fellows. So 46% of fellows between two institutions.....

its because no song by RHCP is just good, they are all great....

On the first exam I ever gave I was terrified for about 20 seconds it took the student to walk from the back of the lecture hall to turn in their exam at the 25 minute mark, did i make it too easy?

Nope the exam was blank they gave up and there was tons of room for partial credit... i was sad...

I have seen this story in progress for many years now, so I am thrilled to see Fatema's manuscript on bioarxiv! Such a cool story.

Also rumor has it Fatema is on the job market AND just scored a K99 so search committees next year keep your eyes open for that app!
www.biorxiv.org/content/10.6...

Shiiiiiiiiiiitttttt.... in less chemistry focused labs some might call that a dream....

*stares at CV* 2018-2024

Have you heard about the AI calculators yet?

The Negroni btw!

Sounds like a happy hour Negroni is in my future in honor of Needhi's birthday, Happy Birthday Needhi!

I am still wondering how long until I see one of these in the wild. I saw the biden ones everywhere in the PGH suburbs.

lol I said this a few days ago and then it was just said on pod save America! Glad we all agree… wish we didn’t have to.

Engineered OAA lectins as selective and sensitive high mannose glycan targeting tools www.biorxiv.org/content/10.64898/2026.03...

This was spearheaded by a wonderful postdoc in the lab Bryce Ackermann with a great supporting cast. I hope yall give it a read and we would be happy to take suggestions on where to send it (or if you are an editor and want it in your journal let me know). #biophysics #glycotime #proteinevolution

To Summarize we used phage display to identify variants with enhanced glycan specificity and enhanced affinity. We characterized these structurally and biophysically and demonstrated their use as tools for glycoform specific biology or for increased antiviral effects.

As OAA was originally discovered as an antiviral and previously I showed it can inhibit SARS-CoV-2 Viral entry, demonstrated that V4V4 and PM6PM6 bivalent OAAs have differential neutralization properties, as V4V4 losses the ability to block viral entry, and PM6PM6 shows a 4x better inhibitor.

To look at the ability of V4 and PM6 to interact with specific glycoforms of proteins we turned to RNAse B which has a single glycosylation site and that can be Man5/6/7/8/9. We used BLI and pulldowns to show that V4 interacts only with the M5 glycoform, while PM6 interacts with all glycoforms

More impressively bivalent V4V4 tuned its selectivity, showing Man-5 binding at 18 nM but Man-6 and Man-7 binidng at 3 and 13 uM, representing a 166x (Man6) and 722x (Man7) fold more selective for Man 5. Based off of this we wanted to demonstrate the use of V4 as a tool in biological systems.

As OAA is symetric with two identical binding sites (which we knocked one out for phage dispaly). We wanted to know if these properties can be tuned by re-installing multivalency. Our bivalent PM6PM6 showed a 26x enhancement in Man-9 binding compared to the bivalent WT!

We believe that this affinity gain offsets the loss in affinity caused by the mutations that confer selectivity. Thus discovering this variant was likely only achievable in a combinatorial library screen. We also noticed that this variant PM6 has enhanced glycan binding!

In order to dissect which mutation(s) conferred which property we used a set of 25 point mutations and BLI. Our data allowed us to bind variants into affinity enhancing, specificity enhancing, weakening or destructive bins. Uniquely we found the two tyrosine mutants cause a increase to Kd!

We solved the crystal structure of bivalent V4V4 bound to the Man-5 core glycan. this revealed a series of interactions that caused a loop shift and the creation of a steric hindrance where the next sugar of a Man-6 glycan would bind. Thus providing a structural basis for specificity.

We screened each variant of interest for binding to HMGs using BLI. From this two variants of interest jumped out right away V4, showing Man-5 specificity, and V6 showing specificity for just Man-5 and Man-6. Showing specificity for a single Glycoform, we further investigated V4.

We fished our library for variants with enhanced binding to Man-5 and over four rounds we observed selection across the loop regions of interest. Using a bioinformatics pipeline we subsequently identified sequences of interest, and cloned them for expression and purification.

OAA is a beta barrel protein that binds glycans in its loop regions, it is incredibly structurally stable, and we can control its valency by mutation. Thus we used it as scaffold to make a 5 x 10*8 variant library of a single carbohydrate recognition domain for phage display.

Glycosylation is a heterogenous process, as such many lectins that bind one glycan, bind similar glycan structures. A great example of this is the OAA lectin that binds high mannose glycans. It recognizes the Man-5 core structure present in all high mannose glycans (HMGs, Man-5/6/7/8/9).