Assembly Line of Enzymes
Deeper into the enzyme immobilization space
When I wrote Solving The Enzyme Immobilization Problem I didn’t realize the impact that the post would have on who reads this newsletter or the depth of the companies out there looking at different ways to immobilize enzymes.
If you don’t know what enzyme immobilization means or why it’s important let me try to briefly explain. If you read my post about MetGen engineering their enzyme to work at pH 11 in order to degrade lignin, then you probably understand the utility of enzymatic catalysis. One thing I didn’t touch on was that production of free enzymes can be laborious and costly. Being able to reuse them would help push costs down and make the technology more accessible for commodity chemicals and thus have a larger impact on the world (I hope positive). There are plenty of current examples of enzymatic catalysis being useful at scale such as in the production of high fructose corn syrup, making better detergents, cleaning solutions, and water purification to name a few.
If we think about traditional industrial chemistry, it’s generally a collection of companies that form a supply chain where each company is specializes at doing specific reactions. For instance, ExxonMobil could extract and refine crude oil and pipe some naphtha distillate over to INEOS who turns that distillate into molten phenol and loads it onto a railcar. Westlake Epoxy might take those railcars of molten phenol and react it with acetone to make bisphenol A and then do a reaction with epichlorohydrin (purchased from Olin) to convert into an epoxy resin they can sell via bulk tank truck. PPG might buy that base epoxy resin and formulate it into an anti-corrosion coating used on the Verrazano Bridge in order to protect the steel from corrosion (not sure why anyone wants to intentionally go to Staten Island though). I just described the supply chain for anti-corrosion coatings, and it can span across the entirety of North America and at least 4 different companies.
As we know from the last two years supply chains can spiderweb across the globe and can be disrupted with ease. Additionally, as the cost of fuel fluctuates, the cost of transport and lack of skilled people to transport your stuff can have further impacts on cost. A general rule (Wittcoff et al.) is to add about 10% of the cost of your purchase to every transport done in the supply chain (at least for chemicals). Not to mention all the hazards in transporting chemicals.
There is an opportunity for some change.
The beauty of synthetic biology I think has always been an internal enzymatic assembly line wherein the cell becomes a miniature factory. In an ideal world a company could be paid to pick-up agricultural waste, feed it to their engineered microbe, and produce the chemicals or materials we need to make our world modern and skip a few of the steps I mentioned above. Instead of 4 companies making a product from crude oil maybe we can get 2 from biomass. While I think synthetic biology holds a lot of promise for the future, provided we can figure out viable economical models, we can also start thinking about how to re-create those metabolic pathways with immobilized enzymes in what is called an enzyme cascade.
From a recent Nature Chemistry paper on the use of enzyme cascades for Pharma:
Enzyme cascades are a powerful technology to develop environmentally friendly and cost-effective synthetic processes to manufacture drugs, as they couple different biotransformations in sequential reactions to synthesize the product. These biocatalytic tools can address two key parameters for the pharmaceutical industry: an improved selectivity of synthetic reactions and a reduction of potential hazards by using biocompatible catalysts, which can be produced from sustainable sources, which are biodegradable and, generally, non-toxic.
While there is a lot more potential value in pharma in terms of margin if successful, I think there are even bigger climate implications regarding transformation of traditional industrial chemistry. If we can change industrial chemistry away from petrochemicals and the traditional energy intensive chemical transformations that require high heat and pressure to work, then I think we’ve got a chance at significantly reducing carbon emissions. Origin Materials attributes about 45% of our carbon emissions to the production of our material world. This transition away from energy intensive chemistry is perhaps even more meaningful than just getting everyone to drive an electric vehicle or replace all of our coal power plants with solar cells and energy storage.
Cascade Biocatalysts
If you spend enough time talking and working with immobilized catalysts you end up discussing the longevity of the specific catalyst. There is often no “perfect” situation where an immobilized catalyst lasts forever. Even the catalytic converter in your car has a designated lifetime, which is supposedly anywhere from 10-25 years in my experience, but what if we could make it better?
That is what James Weltz and Alex Rosay set out to do with figuring out the immobilization technology of Cascade Biocatalysts. The crux of Cascade’s technology is better enzyme immobilization that allows them to put a tiny perfectly folded protein that facilitates room temperature chemical reactions (that’s an enzyme) onto a mechanical support. Cascade views their technology, which is rooted in polymer science, as a “body armor” because it protects the enzyme from losing its shape (folding) and maintains the ability to facilitate chemicals reactions (activity) to the substrates they want to transform.
An example they used to show me recently was on Candida Antarctica Lipase B or CAL-B/CALB. Novozymes famously immobilized CALB on a cross-linked acrylic support to make their product Novozyme 435 (N435). CALB is especially suited to cleaving natural fats or triglycerides into fatty acids and glycerol. Alternatively, in the right conditions you can use CALB to form esters too. If you wanted to see a world full of biodegradable plastics competitive with polyethylene in terms of their properties, you might get there using CALB as a way to build those polymers and then help break them down.
My thesis adviser was obsessed with using N435 for awhile and published a bunch of papers using it to both make polyesters and break them down into their monomers. A recent paper even posed the question if N435 was the perfectly immobilized enzyme:
N435 is perhaps the most widely used commercial biocatalyst in both academy and industry. Here, we review some of the success stories of N435 (in chemistry, energy and lipid manipulation), but we focus on some of the problems that the use of this biocatalyst may generate. Some of these problems are just based on the mechanism of immobilization (interfacial activation) that may facilitate enzyme desorption under certain conditions.
I want to focus on that last part because it speaks exactly to what Cascade is doing with their technology. Essentially, what the authors of the paper are saying is that the method and nature of the immobilization of CALB causes quite a few issues even though the product is considered by many to be a shining example of what enzyme immobilization can do and a standard for the rest of the industry.
Cascade has focused their initial case study comparing their immobilization technology with Novozyme 435. Their early results suggest, and these are their words: “1000x better product (10x better loading, 10x better activity, 10x better longevity) with a comparable price point.” This technology has now been demonstrated on twelve different enzymes, and Cascade is so far 100% successful.
Here are their numbers and their value proposition.
Better Thermal Stability
A big benefit of immobilized enzymes is improved thermal stability and in Figure 1 you can see how much better the activity is for the Cascade system than “free” or soluble CALB or even N435. I personally don’t think the founders finished the reaction or experiment because we don’t see what happens past 70 C. The reason why we get excited for higher activity at higher temperatures is because substrates can become more soluble at higher temperatures, the higher activity means better reactions, and may require less catalyst.
More Reuse
Immobilization of CALB on Cascade’s platform facilitates over 20 reuses of their product while maintaining their original activity. This outperforms N435 again, which lost 75% activity after only 5 reuses. It took 50 reuses of Cascade’s immobilized enzyme to get down to near 50% activity, which means it would take longer to run a reaction than the same catalyst at 20 reuses. This means if you are a customer of immobilized enzymes not only can you in theory pay the same for your N435 catalyst, but you can use it at least 20 more times than your current supplier’s technology. When I wrote about product development needing to be deflationary to be successful this is a prime example.
Better Activity
Cascade’s technology allows them to load more than ten times more enzyme on the same mass of resin as Novozyme while maintaining full enzyme activity. Alternatively, they could load 10x less enzyme and push some of the cost of the product down to produce an equivalent activity that you could reuse at least 20x more times. Or if you want 2022 Red Bull F1 car equivalent in an enzyme catalyst you can get that too.
The Future
The data above is just looking at one enzyme on one support doing one reaction. There is whole area of technology that has been studied using flow reactors and immobilized enzymes and perhaps Cascade’s immobilization technology will unlock continuous enzyme assembly lines.
Do I think that we will get everything in chemicals to be an enzymatic reaction? No, but if we can transition some percentage of the industry then the implications on cost savings would be large enough that whoever can do it first will profit immensely from using current production as a way to set pricing and realize asymmetic returns until the rest of the industry catches up.
In terms of changing or disrupting the chemical industry I’m trying to look for tools and platforms that will enable an economically viable transition from crude oil to biomass. Companies like MetGen, Origin Materials, EnginZyme, and Cascade Biocatalysts will help shape the future of the chemical industry. If you think you are next reply to this email or connect with me on twitter (@tpolymerist)
I think it’s better to adopt early as opposed to waiting to see your competitors do it and try to catch up.
Cascade Biocatalysts are actively looking for early customers who want samples and I think they might still be looking for investors. James and Alex are open to inbound, customer enzyme immobilization projects. Please reach out to alex@cascadebiocatalysts.com to learn more.
Last minute comment from Alex as this went to publication that I've added into the web version:
"This technology has now been demonstrated on twelve different enzymes, and Cascade is so far 100% successful"
12 different enzymes! What more proof does one need?
Nice! Thank you Tony!