 So, hello everybody, as the title says, today I'm going to present you the Nobel Prize in Chemistry that in 2018 was awarded to Francis Arnold and George Smith and Gregory Winter. This is the case, as Liana mentioned, the prize was divided into half for two main researches. The first one is for the Directed Evolution of Anzyme and the second one for the Face Display of Peptides and Antibody. And probably some of you that went red about this prize was a little bit puzzled by the fact that they are awarding one Nobel Prize for two researches, apparently don't even have a word in common. This is not entirely true and these two researchers are going together in the same Nobel Prize because both of them are founded on a very basic concept, which is Directed Evolution. So, during the next 15 minutes, I'm going to try to explain to you what the concept of Directed Evolution is and to do so, I'm going to try to explain you the study from Dr. Francis Arnold because for time constraint, I won't be able to go through both of them. So we will be talking about Directed Evolution and Anzyme. So I'm just going to give you a brief background about the biology behind it and then we are going to dive into the research. So you are probably all familiar with the fact that every living organism on Earth is composed at a smaller level from what we call usually cell. In the small cells, when we focus a little bit more inside the cells, we can actually identify four main components. Carbohydrates, proteins, lipids and nucleic acids are the four main components of cells. They are inside the cells and each of them have a very specific job. And in this time, in this talk, we are going to now focus on the proteins, what they do, which are one of the most abundant and most active components inside the cells. So proteins are very long stretches of small building blocks that are called amino acids that are brought together in a very long line by the cells, reading information inside the DNA. So we have the cells that is able to read some kind of information inside the DNA that tells the cells how to put all these building blocks one after another in a very long stretch, which then, again by the cells, is structured in a 3D structure, which is our folded protein, which is our final version of the protein, which is the one that is active. We can identify inside the cells three different type of proteins, with three main different type of proteins, with three different functions. The first one are structural proteins, which are the proteins responsible for giving the shape to the cell. We have transport and signal proteins, which are the proteins that allow two cells or many different cells to communicate with each other. And finally, we have our enzyme, the focus of the next part of the talk. So enzymes are very specific type of proteins, organized in the same way, this very long complex structure of building blocks that are able to make a chemical reaction happen, binding to a specific substrate, and giving at the end a product. So this chemical reaction happens all the time inside the cells to make many different, various, different type of activity happen. And they are very specific for a substrate and very specific for a product, very specific for a whole reaction. For example, you might be familiar with the concept of enzyme, because you might have already heard people talking about lactase. Lactase is the enzyme that inside the body is responsible for chopping down the lactose inside the milk, allowing you to digest it. And with this example, you might have realized that, since this is a very specific reaction and very efficient in a way, and sometimes we as humans might want to perform the same reaction, but just not inside the body. So for example, right nowadays we want to produce lactose-free milk for lactose intolerance, and enzymes are the most efficient way to do the same activity that they do in the body. So this is what the reason why enzymes have been extensively studied in general in lab research, and now have been moved to the industry setup, because they are the most efficient and the best option to perform this reaction also for our man-made applications. And this is exactly the reason why now we can actually buy this enzyme and use them for many different things. So there are different types of enzymes, according to which type of reaction they are able to make it happen. One of them are enzymes that are able to bind to their substrate and catalyze, to make happen, these chopping down reactions. So at the end, destroy whatever they are able to bind, like lactase. And one of these enzymes is exactly the one that Professor Aldon was studying, which is called sub-chloridin. But since this enzyme, we are taking them from the cells and bringing them to the lab, unfortunately we need to remember that these enzymes are created to work in the cells. So they are able to work only when they are in a very cell-specific condition. One of these main conditions that the cells are restrained from is that the cells are mainly composed by water. So this enzyme only works in a water-based environment. However, when we move away from the lab to the industry and we try to scale up these reactions to make it a lot happen at the same time, we are not always able to work in a water-based environment. And very often we actually work in a known water environment. So like oil, acetone, or alcohol, or whatever. So unfortunately these enzymes in this condition are not able to work anymore. So since the industry application includes many different products that are used everywhere, including detergents, because these enzymes are able to destroy the proteins inside the stains. So you are able to remove the stain. They are used for food processing to, for example, digest the proteins from the milk to make cheese. They are also used for biofuels. So fuels for general fuel-saving, so like cars or other applications, but not made by oil, but made by biological materials. And this is exactly the field of research where Professor Arnold is set in. And this is what she was trying to accomplish. So make the subtilizing protein work in a known water environment so to be able to apply it to a broader industrial application. However, as mentioned before, the enzyme is a very complex structure, in a 3D structure. So it's kind of difficult to understand which of these regions is actually the one responsible for making the reaction happen in a water environment. So which of these regions should we actually focus on to make it change? And even assuming we know which of these regions is the most important one, we don't really know in which way we should modify. So we have a section, a sequence of these building blocks, but we don't really know which way we should modify them in order to obtain the final result that we want to make it work in a different environment. So for this reason, the direct notification of enzyme is very difficult and unfeasible, was not achieved and was not achieved for like from anybody before Professor Arnold brought something new to the field. So I just said that this is unfeasible and impossible and no one has ever done it. This is technically true, but we can also say that it's not completely true. There is someone that actually was able to specifically change something, an enzyme, for example, to make it work with a final specific goal. And this someone is what we all actually refer to usually as nature or mother nature and the process through what this happens is called natural selection and evolution. And this is where the brilliant mind of Professor Arnold came into place because she said, I'm not able to perform this exact modification to make this change happen, but maybe I don't even need to invent anything. I can take inspiration from something that is already happening in the environment and I'm going to bring it and translate it to the chemistry field. So I'm going to give you an introduction on what this concept of evolution and how she was able to bring this to the lab, achieving what she was looking for. So evolution is that concept that has been broadly studied mainly by Darwin. So I'm bringing to you the Darwin example of the giraffes just to make a point. So Darwin was studying population and as we know inside the population that is living, we generally have a variety of specific traits. So in this case, the length of the neck inside the giraffe population can be slightly different between different animals inside the population. And this is kind of a relevant where they are just living with leaves all over the place. However, the moment when we apply a change in the environment, in this case, we replace the small bushes with very tall trees and this is a process that in nature happens naturally through many, many years. Now we realize that the change, the slightly different length of the neck might become relevant. In fact, through many, many years, the process takes many years, we know that the very tall neck giraffes have more chances to see themselves, therefore to reproduce, whereas the short neck giraffes will slowly, slowly die out because they're not able to get the same nutrients as the other, so to reproduce. So through this process, through many, many years of process, at the end what we obtain is an evolved population that is slightly different from the very beginning and has a specific characteristic. The ability to survive in very tall, free environment. And this as you might have realized exactly what Professor Arnold wanted, starting from something that was able to work in water, obtaining a finer result, slightly different from the beginning, able to work in another environment. This is a process that can then be repeated as many times as possible every time a change in environment happens. And this is we call natural selection, this process of selecting according to the animals that is most fitted to survive in an environment and the whole process we call it evolution. So Professor Arnold realized that it was a genius idea, just take this and bring it to the chemistry field. However, the prerequisite for these process to work is to start from a population individual. And as I said before, she was actually starting from just one specific enzyme. So she needed to generate a population of enzyme that was characterized by slightly small differences between each other but still able to perform normally. So as mentioned again before, the differences, generating these differences cannot be done in a very specific target way because again we don't really know which is the region of the protein we need to modify. So the best approach to do so is the one that she came up with which is performing random mutation towards the protein change. And this can be easily achieved because this information comes from information in the DNA. And the DNA is a molecule that is easily manipulated by humans and we can easily modify randomly inside the DNA any information so that at the end we will obtain a slightly different enzyme from the beginning. Applying this random mutation on many, many, many, many elements we can at the end obtain a population of enzymes that are exactly as the one before. So they are exactly able to work inside water condition but they are slightly different between each other. And now we do exactly what Darwin described for the giraffe. We apply a change in the environment so we change from water to non-water environment or at least partially no water environment and then we check which one of these are still able to work in these new environments which one of these giraffes are still able to feed themselves. So we select them through an environment selection. We obtain at the end a subset of the initial population that now we know is actually able to perform in the new environment we want. And this process as the one in evolution can be repeated many, many times. From this population we can now generate new random mutation inside of them, generate a new type, a new population starting from the one from the beginning, apply a new type of change in the environment so going again more away from the water and more to a non-water environment and perform these process all over again and all over again. And this is exactly what Professor Arnold did and this is what we call directed evolution because what we obtain at the end is the same design, slightly different so it has evolved with a new function and is directed because we direction the evolution towards a final goal which is working in the new environment. Professor Arnold applied this very specific procedure to his topic and with four rounds of selection she was actually able to identify an enzyme that was 2,056 times more active than the initial one so she was finally able to obtain something that was able to be used in industry context not more only in the lab and in the cell. This is a process that can be applied to make any tailored enzyme not only to optimize enzymes so to make them work in modified environment increases stability, make the reaction faster and so on but even to create another function for the enzyme so make them perform new reaction or perform the same reaction but on different type of substrate. So this is a very powerful research Professor Arnold wrote to the chemistry field but is that it, is that direct evolution an enzyme or something that goes to end in end and that's all? Well no, so this process can be applied not only to enzyme but to any type of proteins and this is where the second part of the Nobel Prize come into place because the other two winners took the same concept and they applied it to the field of immunology so they use the same approach that they developed and called phase display because uses specific other type of bacterial and so on, the virus and so on and they are now applying this direct evolution in order to produce antibodies that are used in research widely in research but even to produce drugs through a modification of the antibody which is a protein so it can be applied to the same process to fight against virus, cancer, autoimmune disease and now they're even use phase displays this process of direct evolution applied to the field of antibodies to develop vaccine, better vaccine for many different pathology so I hope that I convinced you that this research was kind of revolutionary for the field of chemistry but not only so we are now talking about medicine and biology in general so if you have any question just feel free to ask me or after also about the second part which I was not able to go through thank you That was really interesting topic So we have five minutes for the questions Someone please take this May I ask two questions? I think they are short Rather short I mean one is just yes or no So these three researchers did they receive the Nobel Prize for the approach of directional evolution or for the usage of this approach because as far as I understand the approach is not new so the usage was innovative, right? Then you mean? Yes and the Professor Arnold So for Professor Arnold was the development of direct evolution she developed the process herself for them was the application of direct evolution to phase display in order to then be able to perform all these other applications Okay so the approach was developed by her Yes It's like new, okay That's why she has half of the prize and they both share the other half So they have one fourth each Thank you And the second question is how long did it take to do this whole procedure because it seems to be a bit time consuming, you know? You mean time-wise? Yeah, like So time-wise we are talking about working with bacteria I had to leave out how this process is actually done and it's not a lot of process So bacteria grow overnight and you can grow thousands of them So it doesn't take long to do the selection process Of course all the optimization before takes time, the idea to apply it for real takes time but it's not a time-consuming procedure So you take DNA you modify it, it takes a few hours you put it inside the bacteria takes one day you make the bacteria grow one another day you select them and you repeat it So it's now a long-term procedure Thank you So it's our question So there is no question Thank you