5. Protein Techniques
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So now that we're pretty much experts on protein structure in this chapter, we're gonna focus on protein techniques that biochemist use to study proteins, and we'll start with protein purification techniques. So protein purification is just the process of isolating a single protein of interest so that it's the Onley batch of protein molecule and solution. And there are actually several techniques that can be used to purify a protein for protein purification. And these protein purification techniques exploit unique differences in protein properties. And some of these protein properties include the sizes of the protein, the charges that these proteins have their polarities, they're binding affinities and mawr. And so, in our example below of protein purification notice on the left. Over here, what we have are a bunch of different proteins. We've got green proteins. We've got orange ones, blue ones, black ones and also noticed that we have multiple of the same type of protein. So essentially we just have a big protein mixture here on the left, and so, through the process of protein purification, were able to isolate a single protein of interest so that it's the Onley batch of protein molecule and solution and so notice that our protein of interest is this green protein right here. And so through protein purification were able to essentially isolate all these proteins of interest eso that they're the Onley batch of protein molecule and solution. And so over here, what we have is the purified protein. And so, in our next lesson video, we're going to talk about a typical protein purification strategy. But before we get there, let's get a little bit of practice with this concept of protein purification, so I'll see you guys in that video.
Which of the following is likely the most appropriate meaning of protein purification?
Literally isolating only one single protein molecule.
Isolating a batch of the same exact protein molecule.
Isolating a batch of different protein molecules.
Isolating all the proteins of an organism’s proteome.
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So now that we know what protein purification is, we can talk about a typical protein purification strategy and a typical strategy for protein purification consists of the sequential use of the following five techniques and by sequential. What we mean is that these techniques must be used in this particular order. Now, I don't expect you guys to know a lot about how each of these techniques works and what they do just yet. Eventually, as we move forward in our course, we're gonna talk about each individual technique and more detail. But for now, I just want you guys to focus on the big picture in this video, which is just the order that these techniques are used in a typical protein purification strategy. So the first technique is just protein extraction. And so all this is is just extracting the protein, removing the protein from our source, which are gonna be the cells. Now, our second technique is differentials, centrifuge ation. And this technique allows us to use a centrifuge, which is a machine that spins are samples to separate out components that were not interested in. Now our third technique is called salting out, and this takes advantage of the difference and soluble it, ease between different proteins. And our fourth technique is dialysis, and dialysis allows us to remove small molecules and salts from our solution. And then our last technique is chromatography and chromatography is our most effective purification technique. And so again, we just want to focus on the particular order that these techniques are used. And as we move forward in our course, we'll talk about each individual technique and more detail. So in our next video, we'll get a little bit of practice, and then we'll continue on talking about each of these purification techniques, so I'll see you guys in that video.
A scientist is looking to study a specific protein called mitochondrial transcription factor A (TFAM). Which of the following is the most appropriate sequence of steps for protein purification of TFAM?
Extraction → Dialysis → Salting Out → Differential Centrifugation → Chromatography.
Extraction → Chromatography → Differential Centrifugation → Salting Out → Dialysis.
Extraction → Differential Centrifugation → Salting Out → Dialysis → Chromatography.
Extraction → Salting Out → Dialysis → Chromatography → Differential Centrifugation.