What is a superficial protein?
Several protein complexes that are essential for the lungs for proper functioning are known as the protein of the surface -active substance (SP). The protein of the surface -active substance binds to cell surfaces and helps to relieve surface tension on the lungs, allowing for expansion and contraction. There are four main types of these compounds, each with a different function.
These specific proteins change the properties of the cell surface. The exact function of these complexes depends on the type of protein because there are four main types in the body. These complexes are sensitive to concentration, pH and other environmental conditions.
Surface protein A and D, known as SP-A and SP-D, are hydrophilic because they attract water. SP-B and SP-C are hydrophobic and do not like water. The effects of each of these proteins of the surface -active substance contain significant similarities. Scientists have found that it is difficult to assign a specific role or function to each of them. IT is the most abundant of the four complexes found in the body. There are two different forms independence on the presence of calcium ions. If calcium is present, six trimers that form a complex remains in a closed form, otherwise the SP-A is present in open form.
SP-A function is to help transport other proteins and strengthen the immune system. In particular, this is important for the production of tubular myelin. Tubular myelin is a protein that is decisive for lung cells and allows the lung volume to change during breathing. The more surface -active substances, the lower the surface tension on the lungs, which makes it easier to inflate and blow.
SP-B is necessary for the production of tubular myelin. It is important for life because children born without this composition will die early after birth. The SP-B makes the collapse of large areas by maintaining the layer of the layer and the ability to move.
Of the four types of compound, the SP-C is the smallest. It is also the second most abundant SP found in the body. This is only inlungs and it is the most hydrophobic of four. The main features of this SP-C is to help lipids move and promote compounds to stack into multiple layers.
Protein-D surface active substance is the largest of all surfaces. Unlike other complexes, the lungs are not at the air water interface, but in type II cells that create a different voltage reduction of the compound. The type II cell is an alveolar cell found in the lungs. SP-D is necessary to maintain the correct balance of phospholipids and cell formation used by the immune system, such as macrophages.