Kallikrein is a term used for a subgroup of enzymes referred to as serine proteases. Serine proteases are responsible for cutting peptide bonds found in various proteins. Peptide bonds are chemical bonds created between two molecules, resulting in what is known as an amide. An amide is an organic compound found in items such as some solvents and medications.
The kallikrein enzyme is found in various human bodily organs as well as in the venom of certain snakes. When this enzyme was first discovered, it was thought to be produced by and unique to the pancreas. As science progressed, the kallikrein enzyme was found in saliva, urine, and human blood. These enzymes have since been found in other animals as well, including but not limited to mammals.
Liberating kinins from the kininogens is one of the functions of the kallikrein enzyme family. A kinin is a type of polypeptide, or chain of amino acids. Amino acids are ressponsible for protein production. Kininogens are proteins known as being precursers for kinin.
The kallikrein enzyme is also known for generating plasmin from what is known as plasminogen. The primary role of plasmin is to dissolve blood clots known as fibrin blood clots. These types of blood clots are responsible for forming scabs over a wound as it begins to heal. Plasminogen is the precursor of plasmin and is found in the plasma, or liquid portion of blood.
Drug researchers are actively studying the kallikrein enzyme, as early evidence suggests that changes in this family of enzymes could lead to medical conditions such as cancer over a period of time. Certain kallikrein genes are already in use as tumor markers for prostate cancer, as these enzymes have been found to be elevated when these tumors are present. Further study could lead to earlier detection for many types of cancer, thereby providing a more positive prognosis for those given this much-dreaded diagnosis.
Biomarkers are any substances that can be injected or otherwise introduced into an organism in order to examine the function of bodily organs or systems. These biomarkers can also be used to monitor disease progression. The kallikrein enzyme is not only being studied by scientists for these reasons, but also by drug companies. As research begins to suggest a particular usefulness for this family of enzymes, drug companies hire their own scientists to research pharmaceutical implications of these medical advances.