Components of protein

Protein is a basic substance in the human body. The elements that make up protein are mainly carbon, hydrogen, oxygen and nitrogen, which are the most basic elements of protein. It is a relatively important biological macromolecule in our human body. Protein has more than 20 different amino acids connected to form a polymer. Protein plays an important role in the human body. It is a substance necessary for maintaining life. In addition, some proteins can act as catalysts, enzymes and hormones.

Protein structure

The boundary between proteins and polypeptides is not very clear. Some people believe that based on the number of residues required for the functional domain, if the number of residues is less than 40, it is called a polypeptide or peptide. To perform biological functions, proteins need to be correctly folded into a specific configuration, which is mainly achieved through a large number of non-covalent interactions (such as hydrogen bonds, ionic bonds, van der Waals forces, and hydrophobic interactions);

In addition, disulfide bonds also play a key role in the folding of some proteins, especially secreted proteins. In order to understand the mechanism of action of proteins at the molecular level, it is often necessary to determine the three-dimensional structure of proteins. Structural biology developed from the study of protein structure, using techniques including X-ray crystallography and nuclear magnetic resonance to analyze protein structure.

A certain number of residues is necessary for a given biochemical function; 40-50 residues is usually the lower limit for the size of a functional domain. Protein sizes can range from this lower limit up to several thousand residues.

The currently estimated average protein length varies among different species, generally ranging from about 200 to 380 residues, while the average length of eukaryotic proteins is about 55% longer than that of prokaryotes. Larger protein aggregates can be formed from many protein subunits; for example, thousands of actin molecules aggregate to form protein fibers.

Protein role

1. Constitutes the basic substance in living organisms and is necessary for growth and maintenance of life; 2. Some proteins can act as biological catalysts, namely enzymes and hormones; 3. Materials necessary for the immune function of organisms; 4. Some proteins can cause food allergies.