Hirudin

Hirudin is a special kind of substance made by leeches, which are small, jawless creatures that drink blood. This substance, called a peptide, is found in the leech's salivary glands. It helps prevent blood from clotting, which means it keeps the blood flowing smoothly. This is very important for leeches because when they feed on blood, they need the host's blood to keep flowing after they make a small puncture in the skin.

Leeches, like Hirudo medicinalis, use hirudin to make sure they can feed effectively. Without this substance, the blood would clot too quickly, and the leech wouldn't get enough to eat. Hirudin belongs to a group of molecules that stop certain enzymes from working. These molecules include other substances like haemadin and antistasin, which also have roles in controlling blood clotting.

Hirudin has become very important in medical research and treatments because of its ability to prevent blood clots. Scientists study it to learn how to make better medicines for conditions where blood clots can be dangerous. This tiny substance from a leech helps us understand more about keeping blood healthy and flowing.

Structure

In the late 1800s, a scientist named John Berry Haycraft discovered that leeches secrete a special substance called hirudin, which stops blood from clotting. This helps leeches feed on blood by keeping the host’s blood flowing. Hirudin is made up of 65 tiny building blocks called amino acids, arranged in two parts. One part is tightly folded with three special bonds, while the other part is loose when not attached to anything. Scientists later learned more about its exact makeup in the 1970s. Today, we can create hirudin in laboratories using special methods.

Biological activity

Hirudin is a natural substance found in leeches that helps stop blood from clotting. It works by blocking an important enzyme called thrombin, which is needed to form blood clots. By stopping thrombin, hirudin helps keep blood flowing and can be used to treat certain blood disorders and skin conditions.

Unlike some other blood-thinning medicines, hirudin only targets active thrombin and does not affect many other proteins in the blood. This makes it useful in special medical situations where other treatments might not work as well.

Medical use

Scientists have created ways to make a special protein called hirudin in laboratories using a process called recombinant biotechnology. This helps doctors make medicines that stop blood from clotting too quickly. Some of these medicines include:

• recombinant hirudin from Hansenula (Thrombexx, Extrauma)
• lepirudin (Refludan)
• desirudin (Revasc/Iprivask)
• bivalirudin

These medicines help keep blood flowing in people who need it.