When people think about proteins, they likely think about how meat, fish, and legumes play into a healthy diet. Protein is an essential macronutrient that helps provide the very structure of our muscle tissue. However, proteins are also an integral part of the microscopic functions within the body. In fact, proteins are among the most critical molecules found in the human body.
Surprising Facts About Proteins
As a microscopic molecule, each cellular protein has a specific number of jobs it must perform within the cell. These protein roles, or protein functions, are very diverse and contribute to the proper functioning of our body’s cells and how they contribute to our health. For the most part, a protein’s function depends on its shape – which, in turn, is influenced by the way the protein folds in on itself.
Protein folding and function is a complex topic that has a drastic effect on the functioning of our cells and the human body as a whole. We’ve compiled a list of surprising protein and protein folding facts to summarize just how important proteins really are:
- Proteins are numerous. A current project to explore the human proteome – the catalog of human proteins – has revealed that there are between 20,000 and 100,000 unique proteins in each cell of the human body. When you consider the fact that each has its own job, it’s easy to see just how crucial proteins are.
- Protein folding depends on amino acids. While all proteins are made of a sequence of 22 different types of smaller units called amino acids, the way the amino acids are ordered determines how the protein will fold. Most proteins fold multiple times, resulting in regulated, three dimensional, primary, secondary, tertiary, and quaternary structures dependent on the interactions between its amino acids.
- Protein folding determines function. Only after a protein folds into its natural structure can it assume its function. Some proteins serve as structural proteins to support the cell, while others fold into a tunnel-type shape to allow molecules in and out of a cell and still others fold to expose channels or “active sites” to signal, bind with, or otherwise interact with other molecules.
- Protein folding can fail. Protein folding is a very detailed process that has many potential points of failure along the way. For example, if an amino acid is missing – due to a mutation or mistake in protein production – the protein cannot fold as expected. Even perfectly formed proteins can undergo protein unfolding or misfolding, especially when cell conditions are not ideal.
- Protein folding mistakes can cause disease. Proteins that fail to fold properly can no longer carry out their assigned function, leading to a shortage in proteins that accomplish essential tasks in the body. For example, if there is a shortage of proteins that metabolize a particular sugar or toxin, those substances can build up in the body and cause serious issues. Buildup can lead to toxicity and slow cell growth, as in diseases like cystic fibrosis and some forms of cancer.
- Misfolded proteins can aggregate. Another issue caused by improperly folded and unfolded proteins involves the way these oddly-shaped proteins tend to gather together, or aggregate. Researchers believe clumps of certain misfolded proteins contribute to the onset of diseases like Alzheimer’s, Parkinson’s, and ALS.
Protein Research Continues
While scientists know a great deal about protein folding and how it contributes to cell function, the human proteome project is just beginning. As additional proteins are discovered, much work is still ahead to truly understand their structure and functions. It is hoped that with thorough cataloging of protein types, functions, and structures, researchers will be able to identify and prevent protein misfolding-based diseases more accurately.