Histidine: An Essential Amino Acid in Biochemistry

by Yuvi K - January 7, 2024

Histidine: An Essential Amino Acid in Biochemistry

Histidine (Hindi: हिस्टिडीन) is an essential amino acid, one of the 20 common amino acids found in proteins. Histidine is released from proteins by the action of enzymes called aminopeptidases, and taken up into the body to be used in protein synthesis.

Histidine is especially important in the biochemistry of cells, as it can act as an electron donor or acceptor, a buffer for many biochemical reactions, and an enzyme activator. Histadine lies at the heart of many crucial biological pathways, which makes it a key component in our biochemistry.

Chemical Structure of Histidine

Histidine is composed of a central carbon atom surrounded by three hydrogen atoms, to which two nitrogen atoms are attached. As with all amino acids, the chemical structure consists of an amino group at one end (the amine group), and a carboxylic acid group at the other (the acid group).

The side chain of histidine consists of an imidazole ring, which is responsible for the unique properties of this amino acid. Histidine is an ‘aromatic’ amino acid, which means that its side chain is composed of two benzene rings that overlap.

Role of Histidine in the Body

Histidine plays a number of important roles in the body. In humans, histidine helps to regulate the pH of the stomach and intestines, and also plays a key role in wound healing. It is also a component of a number of enzymes, hormones, and other proteins in the body.

Histidine also helps to produce hemoglobin, a protein in red blood cells that carries oxygen. It also helps to form myelin, which is the protective coating that surrounds nerve cells and helps them to communicate. Histidine also plays a role in immune system function and is important for healthy eyesight.

Dietary Sources of Histidine

Histidine is classified as an essential amino acid, which means that it is not produced in the body and must come from the diet. It is found in high concentrations in animal proteins, such as eggs, milk, and meat. It is also found in some plants, such as seeds, beans, and nuts.

The best food sources of histidine are lean proteins such as fish, poultry, legumes, beans, nuts, and dark green leafy vegetables. In particular, chicken breast and canned tuna are particularly high in histidine.

Health Benefits of Histidine

Histidine has a number of potential health benefits. It can help to reduce inflammation in the body, and may help to reduce joint pains, muscle soreness, and fatigue. It may also help to fight against certain types of cancer by providing antioxidants that can assist in the destruction of cancer cells.

Histidine may also be helpful in treating digestive issues such as ulcers, irritable bowel syndrome, and celiac disease. It can help to reduce the risk of coronary heart disease, and may help to reduce symptoms of depression and anxiety.

Daily Intake of Histidine

The recommended daily intake (RDI) for histidine is 10mg per kilogram of body weight. Therefore, a person weighing 70kg should aim to consume at least 700mg of histidine per day.

Side Effects of Histidine

Although histidine is generally considered to be safe, it is possible that some people may experience side effects if they take too much. These can include digestive problems, dizziness, fatigue, and headaches. People who are pregnant or breastfeeding should not take histidine supplements without consulting their doctor first.

Summary

Histidine is an essential amino acid, one of the 20 common amino acids found in proteins. Its side chain consists of an imidazole ring, and it has a number of important biological functions, including acting as a buffer, electron donor or acceptor, and enzyme activator. It is also important for wound healing, immune system function, and hemoglobin production.

Histidine can be found in a variety of foods, particularly lean proteins such as fish, poultry, legumes, beans, nuts, and dark green leafy vegetables. It is also available as a dietary supplement. The recommended daily intake for histidine is 10mg per kilogram of body weight.

Histidine may have a number of potential health benefits, such as reducing inflammation, fighting against certain types of cancer, and reducing the risk of coronary heart disease. However, people should take care not to take too much, as this can be associated with side effects, such as headaches and fatigue.