Hemolysins or haemolysins are lipids and proteins that cause lysis of red blood cells by destroying their cell membrane. Although the lytic activity of some microbe-derived hemolysins on red blood cells may be of great importance for nutrient acquisition, many hemolysins produced by pathogens do not cause significant destruction of red blood cells during infection. Although hemolysins are capable of doing this for red blood cells in vitro.

As mentioned above, most hemolysins are protein compounds, but others are lipids biosurfactants.[1]

Many bacteria produce hemolysins that can be detected in the laboratory. It is now believed that many clinically relevant fungi also produce hemolysins.[2] Hemolysins can be identified by their ability to lyse red blood cells in vitro.

Not only are the erythrocytes affected by hemolysins, but there are also some effects among other blood cells, such as leucocytes (white blood cells). Escherichia coli hemolysin is potentially cytotoxic to monocytes, lymphocytes and macrophages, leading them to autolysis and death.

Visualization of hemolysis (UK: haemolysis) of red blood cells in agar plates facilitates the categorization of Streptococcus.

In the next image we can see the process of hemolysis by a Streptococcus:

One way hemolysin lyses erythrocytes is by forming pores in phospholipid bilayers.[3][4] Other hemolysins lyse erythrocytes by hydrolyzing the phospholipids in the bilayer.

Due to the importance of hemolysins and the formation of pores, this part looks forward to enhance some more aspects of the process. Many hemolysins are pore-forming toxins (PFT), which are able to cause the lysis of erythrocytes, leukocytes, and platelets by producing pores on the cytoplasmic membrane.

But, in which way does this kind of protein carry out this process?

Hemolysin is normally secreted by the bacteria in a water-resoluble way. These monomers diffuse to the target cells and are attached to them by specific receivers. After this is already done, they oligomerize, creating ring-shaped heptamer complexes.[5]

Originally posted here:
Hemolysin - Wikipedia, the free encyclopedia