What Is a Myelin Protein?

A myelin protein is one of several different proteins that occur commonly with myelin, an important substance in the nervous system. These proteins, together with a mixture of other chemical building blocks, give myelin the ability to block, isolate, and channel electrical impulses. A healthy human body produces two different varieties of myelin, and each of these contains a somewhat different mix of proteins. A deficiency in myelin protein or the loss of this substance can cause several different conditions stemming from the improper functioning of the nervous system.

Nerves in a human body work by sending small electrical impulses from cell to cell. These impulses originate in one nerve cell and travel down a long axon, which is protected by a myelin sheath. As electrical impulses reach the end of the axon, they are detected by the dendrites of the next cell in the chain of nerves. This process allows neural communication to travel smoothly and swiftly throughout the body.

Myelin protein is important in this process because the three main varieties of this protein are key ingredients in the protective sheath of myelin that coats each axon. When myelin is present along an axon in appropriate amounts, electrical impulses travel smoothly to their destinations. If the sheath is damaged, or if the balance between lipids and myelin protein in the sheath is thrown too far off, then impulses do not travel effectively and may either not reach the end of the axon or accidentally jump to trigger the dendrites of a different cell.

The three main varieties of myelin protein are mostly responsible for providing the form and structure of the myelin sheath that protects the axon. These proteins can be thought of as forming the sturdy internal skeleton to which lipids and other molecules attach to form a fully-functional sheath. In the absence of sufficient quantities of myelin protein, a sheath will not form or function properly.

Several conditions are known to have a serious impact on the integrity of the myelin sheath. Multiple sclerosis is one of the best-known of these. In MS, the body’s own immune system attacks the myelin sheath. Over time, this condition causes the nervous system to gradually lose the ability to transmit information reliably and accurately. This, in turn, may lead to both physical symptoms and mental difficulties, as nerves are important both for cognition within the brain and for the effective transmission of instructions from the brain to the various muscles of the body.