Elementary idea of tertiary structure

Definition of the Tertiary Structure of the protein

The tertiary structure of the protein refers to the stage of a polypeptide chain’s development when it becomes functional. When examined at this level, proteins have a distinct three-dimensional form and include distinctive functional groups on their surfaces. These groups allow proteins to interact with other molecules and provide them with their specific functions. The arrangement is achieved with the assistance of chaperones, which move the protein chain around, bringing different groups on the chain closer together to aid in forming links between them. These amino acids that interact with one another are frequently located towards the end of the chain.

When it comes to proteins, the primary structure, a simple chain of amino acids bound together by peptide bonds, determines the higher-order structures, also known as the secondary and tertiary structure of the protein because it dictates how a protein chain folds together. Every amino acid has a characteristic side chain, also known as an R-group, which is responsible for the amino acid’s features.

The loss of a tertiary structure of the protein, such as an enzyme’s function, results in the protein’s inability to perform its function since it has become denatured and has lost its biological function. This commonly occurs when the protein molecule is exposed to temperatures too high for it. However, once the temperatures have returned to normal, the tertiary structure of the protein can be achieved again, if necessary. The main structure appears to be essential in defining the more sophisticated folding.

Interactions Between the Tertiary Structure of the protein

The following are the primary interactions that contribute to the formation of the tertiary structure of the protein. They direct the bending and twisting of the protein molecule, which aids in achieving a stable state. In the presence of covalent interactions, where pairs of electrons are exchanged between atoms, or non-covalent interactions, where pairs of electrons are not shared between atoms, we can witness both types of interactions. Keep in mind that the breakdown of these bonds can result in the denaturation of the protein in question.

Hydrophobic Interactions

They are the most significant factor and driving force in creating the tertiary structure of the protein since they are non-covalent.

Putting hydrophobic (water-hating) molecules in water will cause them to congregate and form big pieces of hydrophobic molecules, which will be difficult to remove. Because some R-groups are hydrophilic (love water) and others are hydrophobic (hate water), all amino acids containing hydrophilic side chains, such as isoleucine, will be found on the protein’s surface. In contrast, all amino acids containing hydrophobic side chains, such as alanine, will aggregate together at the centre of the protein. The hydrophobic core and hydrophilic surface of a protein that forms in water, as the vast majority of them do, are two characteristics that distinguish it from other proteins. This is critical in defining the final design of the tertiary structure of the protein.

Disulfide Bridges

This is a type of covalent connection that is formed by cysteine residues that are in close proximity to one another in space. 

Ionic Bonds

Some amino acids possess side chains that are positively or negatively charged, depending on the amino acid. An amino acid with a positive charge can form a bond with an amino acid that has a negative charge if the two amino acids are near enough together. This bond assists in stabilising the protein molecule.

Hydrogen Bonds

These hydrogen bonds between water molecules in the solution and the hydrophilic amino acid side chains on the molecule’s surface can be observed under a microscope. In addition, hydrogen bonds form between polar side chains, which aid in stabilising the tertiary structure of the protein.

The tertiary structure of proteins can be classified into the following categories:

• Globular Proteins

The vast majority of proteins belong to this category. Globular proteins are shaped like a ball, with hydrophobic amino acids concentrated in the core and hydrophilic amino acids concentrated on the exterior, resulting in a water-soluble molecule. Globular proteins are found in various organisms, including bacteria, yeast, and fungi. Many globular proteins feature domains, which are locally folded sections of the tertiary structure that range in size from 50 amino acids to 350 amino acids. If a protein performs several activities, it is possible to find a single domain in multiple proteins that perform the same function. A protein that performs multiple functions can contain more than one domain, each of which performs a specific function. An excellent example of globular proteins is the enzymes found in our bodies.

• Fibrous Proteins

A fibrous protein is a protein made up of fibres that are often composed of repeated amino acid sequences, resulting in a very well-organised and elongated molecule. Included in this group is cartilage, which serves to provide structural support and is insoluble in water.

You can find some tertiary protein examples below.

• Tertiary protein examples

Keratin

It is one of the best example of tertiary protein, and Keratin is a protein found in your hair, skin, and nails. Keratin is also found in the interior organs and glands of the body. Keratin is a protective protein that is more resistant to scratching and ripping than the other types of cells produced by your body.

Keratin is a protein obtained from many animals’ feathers, horns, and wool and is utilised in hair cosmetics.

Myoglobin

Another tertiary protein example is myoglobin, a protein present in animal muscle cells. It serves as an oxygen storage unit, supplying oxygen to the muscles in use. For example, seals and whales can stay submerged for extended periods because they have a higher myoglobin concentration in their muscles than other species.

Conclusion:

The tertiary structure of the protein refers to the stage of a polypeptide chain’s development when it becomes functional. When examined at this level, proteins have a distinct three-dimensional form and include distinctive functional groups on their surfaces. These groups allow proteins to interact with other molecules and provide them with their specific functions. Hydrophobic Interactions are the most significant factor and driving force in creating the tertiary structure of the protein since they are non-covalent in nature.

 Disulfide Bridges is a type of covalent connection formed by cysteine residues that are close to one another in space. Hydrogen bonds form between polar side chains, which aid in stabilising the tertiary structure of the protein. Globular proteins are shaped like a ball, with hydrophobic amino acids concentrated in the core and hydrophilic amino acids concentrated on the exterior, resulting in a water-soluble molecule. A fibrous protein is a protein made up of fibres that are often composed of repeated amino acid sequences, resulting in a very well-organised and elongated molecule