What is the relationship between the structural composition of a protein and the function of a prote

There is no direct relationship! Look at the structure and arrangement of amino acids! Each protein has a representative amino acid!

The primary structure of a protein refers to the order in which amino acids are arranged and the position of the disulfide bonds, and the higher order structure of a protein refers to the spatial structure.

The primary structure of a protein determines the higher order structure, and the higher order structure determines the biological function.

A classic example of a primary structure-determining character: sickle cell anemia.

The sixth amino acid residue of the n-terminal subunit of normal erythrocyte hemoglobin is glutamate. Normal red blood cells are biconcave disc-shaped.

The sixth amino acid residue at the N-terminus of the subunit of abnormal erythrocyte hemoglobin changes from glutamate to valine.

Glutamate is negatively charged under physiological conditions, while the side chain of valine is a non-polar group, so not only does it change the charge properties of the surface of the three-dimensional structure of hemoglobin, but also adds a hydrophobic tail, creating a "sticky" protrusion that prompts cells to adhere to each other to form fibrous polymers under deoxygenation. This change in hemoglobin causes red blood cells to become sickle-shaped. It is easy to block the capillaries, causing inflammation; Sickle-shaped red blood cells are easily broken and hemolyzed, causing anemia.

A typical example of a higher order structure determines properties: ribonuclease A

After ribonuclease A was treated with mercaptoethanol and urea, denaturation occurred, 4 pairs of disulfide bonds were broken, polypeptide chains were extended, 4 pairs of disulfide bonds were broken by reduction, and the cysteine side chain changed the higher order structure of free sulfhydryl groups and lost biological activity. If a large number of denaturants and reducing agents are removed by dialysis, in the presence of trace reducing agents, the 4 pairs of disulfide bonds are rebuilt in their original positions, the stretched polypeptide chain is refolded into the natural high-order conformation, and the biological activity is restored.

If anything, it is probably that the function of the protein is adapted to the structure, and each domain of the protein performs a function. As it was said upstairs, what structure determines what function.

For example, hemoglobin and carriers are proteins, but their function is to transport, hemoglobin is to transport oxygen or something, and carriers are mainly involved in active transport and assist diffusion.

Another example is enzymes, most of which are proteins, but they are catalytic.

There are also antibodies, which are involved in the immune response and have a role in cell recognition.

The above examples are essentially proteins, but due to their different structures, they all end up with different functions. It can also be said that the structure determines their function.

The primary structure is the basis of spatial conformation, as well as the basis of function. Proteins with similar primary structures have similar spatial conformation and function. If the primary structure changes and affects its function, it is called a molecular disease.

The spatial conformation of proteins is closely related to function. Changes in the spatial structure of proteins can lead to the loss of their physiological functions. After protein denaturation, as long as the primary structure is not destroyed, it can still be refolded under certain conditions and restore its original conformation and function.

1.Relationship between protein primary structure and function (1) Primary structure is the basis of spatial conformation The primary structure of protein is the basis of spatial conformation and the basis of function.

2) Proteins with similar primary structure have similar higher-order structures and functions

3) Amino acid sequences provide important bioevolutionary information

4) Changes in the amino acid sequence of important proteins can cause diseases

If the primary structure changes and affects its function, it is called a molecular disease. For example, the 6th amino acid of the hemoglobin subunit is converted from glutamic acid to valine, which can lead to sickle-shaped anemia. But not every amino acid of the primary structure is important. 

2.Relationship between higher order structure and function of proteins.

The spatial conformation of proteins is closely related to function. The synthesis, processing, and maturation of proteins in living organisms is a complex process, in which the correct folding of polypeptide chains is essential for the formation of their correct conformation and the functioning of their functions. If the folding of the protein is wrong, although its primary structure remains unchanged, the conformation of the protein can still affect its function, and in severe cases, it can lead to the occurrence of disease, which is called protein conformation disease medical educationCollected and organized by the net.

Hemoglobin in adult red blood cells is mainly composed of two peptide chains and two peptide chains (2, 2), with 141 amino acid residues and 146 amino acid residues. The fetal period is mainly 2 2, and the embryonic period is mainly 2 2The four peptide chains of hemoglobin are composed of four subunits, and the conformational changes of each subunit can affect the binding of the subunits to oxygen.

BSE is a group of degenerative lesions of human and animal nerves caused by prion proteins (PRPs), which are infectious, hereditary, or sporadic in onset. The biochemical mechanism of its pathogenesis is the transformation of the normal helical form of PRPC into an abnormal-folded form of PRPSC. in the organism

The denaturation and refolding of ribonuclease and the loss and restoration of its function, ribonuclease is a polypeptide chain composed of 124 amino acids, containing four pairs of disulfide bonds, and the spatial conformation is a globular molecule.

When the natural ribonuclease is treated with -mercaptoethanol in 8mol l urea, the intramolecular tetra-disulfide bond is broken, the molecule becomes a loose peptide chain, and the enzyme activity is completely lost. However, after the dialysis method was used to remove -mercaptoethanol and urea, the enzyme was oxidized and spontaneously folded into its original natural conformation, and the enzyme activity was restored.

Hemoglobin is a tetrameric protein that has oxygenation function to transport oxygen in the blood, and deoxygenated hemoglobin has a low affinity for oxygen and is not easy to bind to oxygen. Once one subunit of the hemoglobin molecule binds to O2, it will cause the conformation of the subunit to change, and cause the conformational changes of the other three subunits successively, which is easy to bind to oxygen, indicating that the changed conformation is most suitable for binding to oxygen.