Protease inhibitor (biology)
Encyclopedia
In biology
and biochemistry
, protease inhibitors are molecule
s that inhibit the function of protease
s. Many naturally occurring protease inhibitors are proteins.
In medicine
, protease inhibitor is often used interchangeably with alpha 1-antitrypsin
(A1AT, which is abbreviated PI for this reason). A1AT is indeed the protease inhibitor most often involved in disease, namely in alpha 1-antitrypsin deficiency
.
there are now 85 families of inhibitors. These families are named with an I followed by a number, for example, I14 contains hirudin
-like inhibitors.
Biology
Biology is a natural science concerned with the study of life and living organisms, including their structure, function, growth, origin, evolution, distribution, and taxonomy. Biology is a vast subject containing many subdivisions, topics, and disciplines...
and biochemistry
Biochemistry
Biochemistry, sometimes called biological chemistry, is the study of chemical processes in living organisms, including, but not limited to, living matter. Biochemistry governs all living organisms and living processes...
, protease inhibitors are molecule
Molecule
A molecule is an electrically neutral group of at least two atoms held together by covalent chemical bonds. Molecules are distinguished from ions by their electrical charge...
s that inhibit the function of protease
Protease
A protease is any enzyme that conducts proteolysis, that is, begins protein catabolism by hydrolysis of the peptide bonds that link amino acids together in the polypeptide chain forming the protein....
s. Many naturally occurring protease inhibitors are proteins.
In medicine
Medicine
Medicine is the science and art of healing. It encompasses a variety of health care practices evolved to maintain and restore health by the prevention and treatment of illness....
, protease inhibitor is often used interchangeably with alpha 1-antitrypsin
Alpha 1-antitrypsin
Alpha 1-Antitrypsin or α1-antitrypsin is a protease inhibitor belonging to the serpin superfamily. It is generally known as serum trypsin inhibitor. Alpha 1-antitrypsin is also referred to as alpha-1 proteinase inhibitor because it inhibits a wide variety of proteases...
(A1AT, which is abbreviated PI for this reason). A1AT is indeed the protease inhibitor most often involved in disease, namely in alpha 1-antitrypsin deficiency
Alpha 1-antitrypsin deficiency
Alpha 1-antitrypsin deficiency is an autosomal recessive genetic disorder caused by defective production of alpha 1-antitrypsin , leading to decreased A1AT activity in the blood and lungs, and deposition of excessive abnormal A1AT protein in liver cells...
.
Classification
Protease inhibitors may be classified either by the type of protease they inhibit, or by their mechanism of action. In 2004 Rawlings and colleagues introduced a classification of protease inhibitors based on similarities detectable at the level of amino acid sequence. This classification initially identified 48 families of inhibitors that could be grouped into 26 related superfamily (or clans) by their structure. According to the MEROPS databaseMEROPS database
MEROPS is an on-line database for peptidases and their inhibitors. The classification scheme for peptidases was published by Rawlings & Barrett in 1993, and that for protein inhibitors by Rawlings et al. in 2004.-Overview:...
there are now 85 families of inhibitors. These families are named with an I followed by a number, for example, I14 contains hirudin
Hirudin
Hirudin is a naturally occurring peptide in the salivary glands of medicinal leeches that has a blood anticoagulant property...
-like inhibitors.
By protease
Classes of proteases are:- Aspartic protease inhibitors
- Cysteine protease inhibitors
- Metalloprotease inhibitorMetalloprotease inhibitorThere are three classes of commonly used inhibitors for metalloproteinases.* In vitro, EDTA, 1,10-phenanthroline and other chelating compounds lower the concentration of metal to the point where the metal is removed from the enzyme active site....
s - Serine protease inhibitors (serpins)
- Threonine protease inhibitors
- Trypsin inhibitorTrypsin inhibitorTrypsin inhibitors are chemicals that reduce the availability of trypsin, an enzyme essential to nutrition of many animals, including humans.There are four commercial sources of trypsin inhibitors....
s- Kunitz STI protease inhibitorKunitz STI protease inhibitorKunitz STI protease inhibitor is a type of protein contained in legume seeds which functions as a protease inhibitor. Kunitz-type Soybean Trypsin Inhibitors are usually specific for either trypsin or chymotrypsin...
- Kunitz STI protease inhibitor
By mechanism
Classes of inhibitor mechanisms of action are:- Suicide inhibitor
- Transition state inhibitor
- Protein protease inhibitor (see serpins)
- Chelating agents
Compounds
- AprotininAprotininThe drug aprotinin , is the bovine version of the small protein basic pancreatic trypsin inhibitor, or BPTI, which inhibits trypsin and related proteolytic enzymes. Under the trade name Trasylol, aprotinin was used as a medication administered by injection to reduce bleeding during complex surgery,...
- Bestatin
- Calpain inhibitor I and II
- Chymostatin
- E-64E-64E-64 is an epoxide which can irreversibly inhibit a wide range of cysteine peptidases.The compound was first isolated and identified from Aspergillus japonicus in 1978., and has since been shown to inhibit many cysteine peptidases E-64 is an epoxide which can irreversibly inhibit a wide range of...
- LeupeptinLeupeptinLeupeptin, also known as N-acetyl-L-leucyl-L-leucyl-L-argininal, is a naturally occurring protease inhibitor that can inhibit cysteine, serine and threonine peptidases....
(N-acetyl-L-leucyl-L-leucyl-L-argininal) - alpha-2-Macroglobulin
- Pefabloc SC
- PepstatinPepstatinPepstatin is a potent inhibitor of aspartyl proteases. It is a hexa-peptide containing the unusual amino acid statine , having the sequence Isovaleryl-Val-Val-Sta-Ala-Sta...
- PMSFPMSFIn biochemistry, PMSF is a serine protease inhibitor commonly used in the preparation of cell lysates. PMSF does not inhibit all serine proteases. It is rapidly degraded in water and stock solutions are usually made up in anhydrous ethanol, isopropanol, corn oil, or DMSO...
(phenylmethanesulfonyl fluoride) - TLCK
- Trypsin inhibitorTrypsin inhibitorTrypsin inhibitors are chemicals that reduce the availability of trypsin, an enzyme essential to nutrition of many animals, including humans.There are four commercial sources of trypsin inhibitors....
s