Team:WalthamHS BioHawks/Project/HumanPractices


Human Practices

The enzyme subtilisin has many uses. We focused our project on the stain fighting ability of subtilisin. It has the ability to hydrolyze the peptide bonds that hold together all proteins. This enzyme is environmentally friendly, meaning that it can be readily degraded back into the earth. It also does not produce the harmful side effects or allergic reactions that the harsh chemicals in laundry detergent can cause. Subtilisin is therefore a green alternative in the detergent field.


Subtilisin can cause a respiratory allergy in some people when they come in contact with it in detergent. Reactions differ with the frequency, magnitude, and duration of the exposure. These cases however, are very rare. Because of the low concentrations in detergent, subtilisin is not a concern for skin or eye irritation. There are no major health concerns for the use of subtilisin in laundry and cleaning products.

Alternate Uses: Blood Thinning

Blood clotting, or coagulation, is the process in which mature blood platelets and fibrin (a protein) combine to form a liquid gel. This gel forms blood clots to prevent blood loss when repairing a damaged blood vessel. This process occurs naturally in the circulatory system. Sometimes blood clots form in places and at times where a person does not need it. These clots can be caused by heart problems, stroke, obesity, or smoking. If a clot forms in or near major organs, serious problems can occur, such as:

Embolism: The result of an embolus (any object in the circulatory system that can clog arteries or capillaries during circulation) blocking a blood vessel in the circulatory system, causing vascular occlusion (a cut off of the bloodstream due to a blockage), which could affect a distant part of the body.

Thrombosis: The formation of a blood clot by platelets and fibrin which can clog blood vessels, possibly causing oxygen deprivation if the clog is significant and leading to lactic acid accumulation (an acid that is toxic in large quantities), which can then lead to tissue cell death and prevent oxygen from reaching the rest of the body.

Subtilisin has the ability to break down these blood clots. Subtilisin is a serine protease, an enzyme that degrades proteins by hydrolyzing peptide bonds. Subtilisin enzymes use nucleophilic attacks (they add an electron) to hydrolyze peptide bonds by removing an OH group from the serine residue of the protease and an O from the neighboring carboxyl group of the amino acid chain. This cleaves the peptide bonds between amino acid chains. Clots are formed partially by fibrin, an insoluble protein. Ser-221 is the part of the subtilisin enzyme that blocks the active site in the blood clots, preventing the substrate from binding. This blocks further clotting, while also breaking down the fibrin in the clot. Many potential deaths from blood clots could be prevented if the blood clots could be degraded by subtilisin.