Peptides are small chains of amino acids that play a vital role in the functioning of living organisms. They’re essentially the smaller versions of proteins. These tiny molecules are found in everything from our cells to the hormones that regulate our bodies. But what exactly are peptides, and how do they work?
The Basics of Peptides
Peptides are made up of small units called amino acids, which are linked together in a specific sequence. The number of amino acids in a peptide can vary, but most peptides have less than 50 amino acids.
Peptides are classified into two main categories: short peptides, which have less than 50 amino acids, and long peptides, which have more than 50 amino acids. Short peptides are also called oligopeptides, while long peptides are called polypeptides.
People may confuse peptides with proteins. Both proteins and peptides are made up of amino acids, but peptides contain far fewer amino acids than proteins. Like proteins, peptides are naturally present in foods. Some examples include:
| Food | Peptides |
|---|---|
| Eggs | Ovomucoid, ovalbumin |
| Milk | Casein, lactoglobulin |
| Meat (beef, chicken, pork) | Collagen, elastin |
| Fish | Myosin, actin |
| Legumes (beans, lentils) | Legumin, prolamin |
| Nuts and seeds | Globulin, albumin |
| Soy | Glycinin, conglycinin |
| Wheat | Glutenin, gliadin |
| Cheese | Kasein, lactalbumin |
| Yogurt | Lactoglobulin, immunoglobulin |
Peptides in the Body
Peptides play a wide variety of roles in the human body. One of the most important functions of peptides is in the formation of proteins, which are long chains of amino acids that basically do all the work in a cell. Proteins make up the enzymes that power many chemical reactions and the hemoglobin that carries oxygen in your blood. There are at least 10,000 different proteins that make you what you are and keep you that way.
Peptides help regulate the body’s metabolism, including the hormones insulin, which regulates blood sugar levels, and ghrelin (the hunger hormone), which regulates appetite. Peptides also play an important role in the immune system, including the formation of antibodies that help fight off infections.
Studies have found that ingesting certain peptide-rich foods or supplements may improve the health of the skin, hair, muscles, and immune system.
Peptides in Medicine
Peptides have also found a wide range of applications in medicine, from treating cancer to managing diabetes. One of the most promising areas of peptide research is the development of new cancer therapies. Peptides have been found to be effective in targeting and destroying cancer cells while leaving healthy cells unharmed. For instance, peptide vaccines are designed to elicit highly targeted immune system responses, thus avoiding allergic or reactive sequences, creating and spreading tumor T cells to control or kill cancer cells.
Many hormones are peptides, including insulin and GLP-1. These peptides provide key information to cells that affect metabolism, such as by controlling blood sugar. Peptides pass on this information by binding to and activating specialized receptor proteins on the outside of a cell.
Biologists often imagine the peptide as a key that fits into and turns the receptor’s lock. Just like for keys, the right shape is critical for a peptide to work properly, which is why some research groups are busy manipulating peptides to come up with different shapes that could work as new drugs, especially for diabetes.
There is some research being done on the use of certain peptides as a potential anti-aging treatment. For example, one study found that a peptide called epitalon may increase telomerase activity, which could potentially slow down the aging process. However, more research is needed to fully understand the effects of peptides on aging and whether they can be used as an effective anti-aging treatment.
In terms of peptides and muscle growth, certain peptides have been shown to have anabolic effects on muscle tissue. For example, a peptide called IGF-1 (insulin-like growth factor 1) has been found to increase muscle mass and strength. Collagen peptides and creatine are also known to promote muscle repair and boost muscle fiber growth and are often used as supplements.
Other researchers are finding very creative ways to use peptides from nature. A team of MIT researchers managed to tweak peptides found in wasp venom so that it only kills bacteria, and leaves good cells alone. Similarly, scientists at the Institute for Research in Biomedicine Barcelona want to use peptides from scorpion venom to make new drugs that are able to breach the blood-brain barrier more easily.
Synthetic Peptides
Peptides can also be synthesized in a laboratory, which has opened up new possibilities for their use in medicine. Synthetic peptides are used in a wide range of applications, including drug development, diagnostic testing, and vaccine production. The synthetic peptides market is expected to swell to $10 billion by 2032 with a year-over-year growth rate of 8.2%.
One of the major advantages of synthetic peptides is that they can be made to precise specifications, making them more effective and selective in their targets. Additionally, synthetic peptides can be mass-produced, making them more readily available and affordable.
The bottom line
Ultimately, there’s much we don’t know about peptides and future research will uncover more about them and their uses — but we’ve also learned quite a lot about them.
To sum it up, peptides are small chains of amino acids that play a vital role in the functioning of living organisms. From the structural components of cells to the hormones that regulate our metabolism, peptides are essential for life. Peptides have also found a wide range of applications in medicine, from treating cancer to managing diabetes. With the ability to synthesize peptides in a laboratory, new possibilities for their use in medicine have opened up.
