Solubility of Proteins help

[deleted-621706]

Hi, I was thinking about doing the "Solubility of Proteins" project. And in my research, I came across diseases that don't have to do with bacteria or viruses, but incorrect protein folding such as diabetes and Alzheimer's. I am very interested in this and I want to do an experiment that has to do with how/why proteins get incorrectly folded and how to avoid this problem in this first place. But the problem is I have no idea how to do this as my project or if it is even possible to do this without lab equipment and such because I do not have access to these resources. If it is, can you please help me find what materials and how I would go about doing this. Also, if there is any other experiment that is similar to this idea that you have I would love to know about it.
Now even if this is not possible I am still very interested in this project but I have some questions that haven't been answered in my research. I would be so thankful if you could answer these questions for me.
1. Can insoluble proteins be a problem in our bodies and not just in experiments and how can they be a problem?
2. Are there insoluble proteins in food in general?
3. Is there a way to test insoluble proteins in some junk food/ other foods?

Thank you so so much for reading this and helping me, I really appreciate it.

[deleted-744967]

Hi, sorry for the late response. You are asking about two different things here, protein solubility, and protein misfolding. Misfolded proteins can be soluble or insoluble. Also, correctly folded proteins can be insoluble in water but soluble in fat, for example.

Completely Insoluble proteins in foods (misfolded or not) don't seem like they would be an issue to me, though someone may correct me on that. I would think that they would just go right through you, or be unfolded and degraded.

You've probably heard of trans-fats, which are man made, and can cause disease. That wasn't a solubility issue, it was the fact that the shape of those fats made it easy for them to stack together, and they could then clog your arteries. But that was their chemical structure, not a folding/misfolding issue.

So, there are ways to do experiments (possibly at home?) to look at protein solubility. However, the fact that your protein is insoluble doesn't mean that it has misfolded. You've just made a liquid that it can't dissolve into. I wrote more about that down below, if you wanted to experiment with it.

The proteins in Alzheimer's, like Tau, become aggregates (globs) because they misfold, and become sticky. This misfolding can happen because of small mutations in the DNA, which translate into small changes in the protein. It can also be because the other proteins responsible for 'tagging' and 'untagging' Tau (this is necessary for Tau to work correctly) aren't doing their jobs. Typically a cell notices misfolded proteins and degrades them, making them harmless, but misfolding can get out of hand, and overwhelm the cell.

Regarding proteins in food - protein extraction is not easy, and requires lots of sophisticated equipment, especially if you want to identify the proteins you find. But food proteins are, as far as I know, not a significant source of disease causing proteins.
There is one exception to this, which you might want to read about, cause its reallllly cool and scary. These are proteins called prions. Prions are a misfolded protein, but when they come into contact with a correctly folded version of themselves, they cause that next protein to misfold as well. This can happen with other proteins, like Tau. But with prions, the misfolding spreads throughout the brain, and eventually it (over maybe a decade) kills normal cells and causes there to be holes in your brain. This looks like dementia, and then kills you. You CAN get this from your diet, if you eat the BRAIN of an infected animal. This is Mad Cow Disease, and others. Anyway, this is an area of ongoing research.

Regarding solubility:
If you want to do experiments in that direction: If you have a protein in a solution (dissolved), you can alter that solution (typically with salts or acid/base) in ways that cause the protein to 'crash' out of solution, or aggregate and fall to the bottom of the container. If you have enough protein and the right reaction, that will be a visibly obvious process, and it can look pretty cool. If you want to pursue that, your chemistry teacher could hopefully help you find a project to go in that direction.

If you have more questions, please ask! I'm sorry this didn't give you much to go on regarding a project, but the solubility question might be a lot of fun.