For those who are just first learning about click chemistry, it makes attaching two larger molecules together very, very simple. It can be done under very gentle conditions (like in water), and has exceptional selectivity. Like it's so selective you really don't need to worry about other things happening on the timescales these reactions occur and can be cleaned up (an hour). There are two types of click chemistry, one that uses copper as a catalyst and one that doesn't. They both opened the world of chemically "stapling" two things together to literally all bench scientists. I cannot overstate how transformative this has been to biological science.
A specific example would describe Bertozzi's work - where sugars with a chemical "handle" are installed on to the cell surface. You can then click something like a fluorophore onto the sugars with handles to figure out where these specific sugars are on a cell surface.
You can do that (glue together two tiny molecules of arbitrary size) but the connector that you get that joins the two pieces in the resulting molecule is not arbitrary.
Using the above chemistry, you can attach DNA oligos to lipids, DNA oligos to proteins, fluorophores to DNA, fluorophores to proteins at particular locations or other complex drugs to DNA, protein or lipids.
Once you get DNA oligos in there you can do computation, as X binds X', and Y to Y'. So you can have all sorts of complex synthetic & designed interactions using chemistry that is both seamless and doesn't interfere with normal molecular biolgy.
Once you have proteins, you can localize particular chemistries.
This sounds mind-blowing and if it is transformative as you state, then why did it take so long to award it the prize, have all the most recent previous winners been more worthy?
It can sometimes take a long time to get a prize awarded. Like I believe Einstein didn't get his prize for years and years after he discovered Relativity and even when they awarded it to him it was only for the photo electric effect, which while important, wasn't perceived as his largest contribution
That was one of the most fundamental scientific discoveries (well, explanation for an unexpected failure of theory to predict experiment) of all time. In particular, the idea of wave packets replacing particle and wave representations was quite helpful.
> Before 1940, Nobels were awarded more than 20 years after the original discovery for only about 11% of physics, 15% of chemistry and 24% of physiology or medicine prizes, respectively. Since 1985, however, such lengthy delays have featured in 60%, 52% and 45% of these awards, respectively.
Yeah I think the concept is very cool and probably has lots of potential, but the fact that not even most scientists I know have heard of it implies that is yet a niche area that hasn't yet had a major impact in applications.
It's not new, so if someone didn't already know about it, then they are probably unlikely to be in a position to take advantage of it, because it is already how a lot of synthesis in this field is done.
It seems “simple” from a chemistry perspective. But as pointed out, the special part is that this is simple chemistry, _that also works in standard biological conditions_ without harming biology: bio-orthogonal. So it allows complex chemistries to be brought into biological contexts easily and completely. So the discoveries made with this novel chemistry will be biological in nature. That makes for an awkward audience when one is siloed either on the chemistry side or the biology side and can’t quite see how much of a door is opened when you combine the disciplines.
Now many years ago, I was in a chemical biology lab (= interrogating/modifying "biology" with "chemical" tools, half organic synth half pharma/bio) around the time that the term "click chemistry" became popular, and the PI got really fired up about it. Lots of other lab groups in adjacent departments were also really fired up about it.
Side note, "click chemistry" is kind of a marketing term in that it describes a process for modular assembly of moieties in one step in "biocompatible" conditions i.e. water without much poison in it, but which doesn't actually describe how to do that.
The first realization of this vision (or at least the first previously discovered system described as click chem) was copper catalyzed azide-alkyne cycloaddition, and for quite a while this was the only "click" reaction.
Omitting for brevity all the things that were attempted and reasons for doing so as they've been elaborated elsewhere in sibling threads, it was basically impossible to get anything working on/in actual living cells (or "embalmed" cells) although the "click" reaction worked fine in isolation. The parameter space here is pretty big; pharmacology of the things, copper concentration, temperature, time, doing all kinds of things to the cells, and we never figured it out, so it's tricky to find a root cause. One failure mode seemed to be that the copper catalyst caused protein aggregation and the labels being added stuck to the aggregates better than they stuck to the "click handle" alkyne, and there were other failure modes more related to pure pharmacology that probably also contributed (e.g. when the drug sticks to the target it does so in a position that blocks the alkyne "click handle" from being accessible). It was also impossible to reproduce a lot of high profile click labeling papers.
That point now seems like the trough of the hype cycle, so to speak. Apparently Bertozzi's subsequent work with strain promoted cycloadditions (= no protein-aggregating copper) is much more useful.
I'm guessing other people with negative commentary got burned by the early promises of click chem in the real world -- Also, that Sharpless got it for an abstract "product vision" (the award is because "he coined the concept of click chemistry, which is a form of simple and reliable chemistry"), Meldal got it for the CuAAC reaction which actually sucks for biology, and Bertozzi's work doesn't stand on its own.
The site is pretty confusing thought, I don't think I could have found it myself. Now I know the link exists I can find it, but I think putting it behind a dropdown on a box labeled "Summary", and labeling it "Popular Chemistry" isn't great for having people find it.
maybe this is why his second so late... when Sanger fourth perform important found on sequencing something, council told him some like: "we know it is important, but bro you had have three on secequcing something".
That was my first thought, and then I was amazed at how dominant the Nobel photo was in a DDG image search 30 minutes after it was announced. Now a few hours later and it's only Nobel affiliated pictures in the first ~50.
This is the second Nobel Prize in Chemistry awarded to Karl Barry Sharpless. In 2001, he was awarded half of the Chemistry prize “for his work on chirally catalysed oxidation reactions”.
People are missing the point. It's not the click that matters. It's the bio-orthogonal part.
This lets me grow cells with one of the click substrates, say, a methionine substitute that incorporates into every protein, purify out my protein, and then easily do chemistry on that. That's near invaluable.
I can grow a virus and put a different click substrate in each of the DNA, protein, and lipids. Then I can infect cells, and mid-infection, separately label each macromolecule a different color. Then, I can figure out what parts of the virus go into the cell, which sheds light on the mechanism of entry.
Having it bio-orthogonal means the biology is preserved and nothing is messed up until the moment of observation.
What "different click substrates" are you talking about? As far as I remember There's only one class that's been developed (alkyne azide cycloaddition) -- sharpless really wants norbornene to take off but no one has developed that afaict - and of these only one that can be done in vivo (cyclooctyne + azide); the others require copper catalyst which is not awesome for living cells.
> ... methionine substitute that incorporates into every protein, purify out
This is crazy labor intensive, I feel like if you are at this point in considering using this to understand a biological you have really burned through a lot of simpler, more established, and easy to calibrate techniques.
Fair. This holds a place in my mind as "basically the same as alkyne - azide" since Tetrazzine is "more or less azide" and dbco is "more or less cyclooctyne". More to the point of the thread, I don't think the Tetrazzine/dbco is orthogonal to alkyne-azide -- they will cross-react -- am I wrong about that?
Apologies -- tetrazine reacts principally with trans-cyclooctenes. So azide/DBCO would be the orthogonal group. To the best of my knowledge, those two pairs do not cross-react.
Yes, they are all the same chemical addition, but I can label them orthogonally. I can incorporate an azo-amino acid, and click a green alkyne. I can incorporate an alkyne nucleotide, and click a blue azide, etc.
>This is crazy labor intensive, I feel like if you are at this point in considering using this to understand a biological you have really burned through a lot of simpler, more established, and easy to calibrate techniques.
I don't think you are understanding what I'm saying here. What are you saying is labor intensive, purifying protein? That's an incredibly common technique. Yes it's labor intensive, but it's the only way to do huge amounts of experiments. If you're saying click chemistry is labor intensive, well, you're wrong, it's a couple hour experiment, most of which is waiting for incubations.
Thanks for the explanation. This seems amazing, but could you kindly clarify how adding glycans to a cell is guaranteed to not disturb biological function?
Former chemist here. I worked in a lab where our main goal was to attach a special fluorophore (= fluorescent molecular probe) to a protein so we could observe how it changes conformation under different conditions. The way we did that was with click chemistry: we incorporated a synthetic amino acid (homopropargylglycine) into the protein and then used a copper-catalyzed click reaction to attach the probe to the synthetic amino acid. (Specifically this reaction: https://en.wikipedia.org/wiki/Click_chemistry#Copper(I)-cata...). It's definitely cool stuff.
58 comments
[ 3.4 ms ] story [ 118 ms ] threadI'd accept:
- elucidating a new signal transduction pathway
- discovering an uncharacterized enzyme
- measuring a biochemical constant of a known molecule (Kd e.g.)
- discovering a new drug target that then gets exploited
Once you get DNA oligos in there you can do computation, as X binds X', and Y to Y'. So you can have all sorts of complex synthetic & designed interactions using chemistry that is both seamless and doesn't interfere with normal molecular biolgy.
Once you have proteins, you can localize particular chemistries.
See https://nautil.us/this-philosopher-helped-ensure-there-was-n... for the story.
That was one of the most fundamental scientific discoveries (well, explanation for an unexpected failure of theory to predict experiment) of all time. In particular, the idea of wave packets replacing particle and wave representations was quite helpful.
https://www.nature.com/articles/508186a
> Before 1940, Nobels were awarded more than 20 years after the original discovery for only about 11% of physics, 15% of chemistry and 24% of physiology or medicine prizes, respectively. Since 1985, however, such lengthy delays have featured in 60%, 52% and 45% of these awards, respectively.
Honestly imo the coolest click chemistry application was as a two-component bonding glue for copper pieces
It's not new, so if someone didn't already know about it, then they are probably unlikely to be in a position to take advantage of it, because it is already how a lot of synthesis in this field is done.
Imagine lego, but with chemistry.
Side note, "click chemistry" is kind of a marketing term in that it describes a process for modular assembly of moieties in one step in "biocompatible" conditions i.e. water without much poison in it, but which doesn't actually describe how to do that.
The first realization of this vision (or at least the first previously discovered system described as click chem) was copper catalyzed azide-alkyne cycloaddition, and for quite a while this was the only "click" reaction.
Omitting for brevity all the things that were attempted and reasons for doing so as they've been elaborated elsewhere in sibling threads, it was basically impossible to get anything working on/in actual living cells (or "embalmed" cells) although the "click" reaction worked fine in isolation. The parameter space here is pretty big; pharmacology of the things, copper concentration, temperature, time, doing all kinds of things to the cells, and we never figured it out, so it's tricky to find a root cause. One failure mode seemed to be that the copper catalyst caused protein aggregation and the labels being added stuck to the aggregates better than they stuck to the "click handle" alkyne, and there were other failure modes more related to pure pharmacology that probably also contributed (e.g. when the drug sticks to the target it does so in a position that blocks the alkyne "click handle" from being accessible). It was also impossible to reproduce a lot of high profile click labeling papers.
That point now seems like the trough of the hype cycle, so to speak. Apparently Bertozzi's subsequent work with strain promoted cycloadditions (= no protein-aggregating copper) is much more useful.
I'm guessing other people with negative commentary got burned by the early promises of click chem in the real world -- Also, that Sharpless got it for an abstract "product vision" (the award is because "he coined the concept of click chemistry, which is a form of simple and reliable chemistry"), Meldal got it for the CuAAC reaction which actually sucks for biology, and Bertozzi's work doesn't stand on its own.
https://en.wikipedia.org/wiki/Click_chemistry
The site is pretty confusing thought, I don't think I could have found it myself. Now I know the link exists I can find it, but I think putting it behind a dropdown on a box labeled "Summary", and labeling it "Popular Chemistry" isn't great for having people find it.
https://www.nobelprize.org/prizes/chemistry/2001/press-relea...
https://en.wikipedia.org/wiki/Karl_Barry_Sharpless
I haven't looked yet at how many people have been awarded multiple Nobels in the same field.
This lets me grow cells with one of the click substrates, say, a methionine substitute that incorporates into every protein, purify out my protein, and then easily do chemistry on that. That's near invaluable.
I can grow a virus and put a different click substrate in each of the DNA, protein, and lipids. Then I can infect cells, and mid-infection, separately label each macromolecule a different color. Then, I can figure out what parts of the virus go into the cell, which sheds light on the mechanism of entry.
Having it bio-orthogonal means the biology is preserved and nothing is messed up until the moment of observation.
> ... methionine substitute that incorporates into every protein, purify out
This is crazy labor intensive, I feel like if you are at this point in considering using this to understand a biological you have really burned through a lot of simpler, more established, and easy to calibrate techniques.
I can click on a strep tag, or a his tag, or a fluorophore of any different color. See: https://clickchemistrytools.com/
Yes, they are all the same chemical addition, but I can label them orthogonally. I can incorporate an azo-amino acid, and click a green alkyne. I can incorporate an alkyne nucleotide, and click a blue azide, etc.
>This is crazy labor intensive, I feel like if you are at this point in considering using this to understand a biological you have really burned through a lot of simpler, more established, and easy to calibrate techniques.
I don't think you are understanding what I'm saying here. What are you saying is labor intensive, purifying protein? That's an incredibly common technique. Yes it's labor intensive, but it's the only way to do huge amounts of experiments. If you're saying click chemistry is labor intensive, well, you're wrong, it's a couple hour experiment, most of which is waiting for incubations.