Potato carboxypeptidase inhibitor
Encyclopedia
Potato carboxypeptidase inhibitor (PCI) is a naturally occurring protease inhibitor
peptide in potatoes that can form complexes with several metallo-carboxypeptidase
s, inhibiting them in a strong competitive way with a Ki
in the nanomolar range. PCI consists of 39 amino acids (MW
4295 Da
) forming a 27-residue globular core stabilized by three disulfide bridges and a C-terminal tail with residues 35-39. PCI contains a small cysteine
-rich module, called a T-knot scaffold, that is shared by several different protein families, including the EGF
family.
is inhibition of receptor dimerization and receptor trans-autophosphorylation
induced by epidermal growth factor (EGF). PCI blocks the formation and activation of ErbB1
/ErbB-2 (EGFR and HER2) heterodimers that have a prominent role in carcinoma
development.PCI also inhibits transforming growth factor alpha (TGF-alpha).
In addition for pancreatic enzymes carboxypeptidase A
and B, PCI also inhibits carboxypeptidase R without affecting the activity of carboxypeptidase N in the circulation and have therefore use in thrombolytic therapy (blood clot lysis).
Protein kinase
Chemotherapy
Thrombolysis
Cancer research
Protease inhibitor
Protease inhibitor can refer to:* Protease inhibitor : a class of medication that inhibits viral protease* Protease inhibitor : molecules that inhibit proteases...
peptide in potatoes that can form complexes with several metallo-carboxypeptidase
Metalloexopeptidase
A metalloexopeptidase is a type of enzyme which acts as a metalloproteinase exopeptidase.The term "metallocarboxypeptidase" is sometimes used to describe a metalloexopeptidase carboxypeptidase....
s, inhibiting them in a strong competitive way with a Ki
KI
Ki or KI may refer to:* .ki, the ISO 3166-1 alpha-2 country code top level domain for Kiribati*Ki., an abbreviation for the Book of Kings in Judaeo-Christian religious texts* Ki * Ki , a Japanese syllabic character...
in the nanomolar range. PCI consists of 39 amino acids (MW
Molecular mass
The molecular mass of a substance is the mass of one molecule of that substance, in unified atomic mass unit u...
4295 Da
Atomic mass unit
The unified atomic mass unit or dalton is a unit that is used for indicating mass on an atomic or molecular scale. It is defined as one twelfth of the rest mass of an unbound neutral atom of carbon-12 in its nuclear and electronic ground state, and has a value of...
) forming a 27-residue globular core stabilized by three disulfide bridges and a C-terminal tail with residues 35-39. PCI contains a small cysteine
Cysteine
Cysteine is an α-amino acid with the chemical formula HO2CCHCH2SH. It is a non-essential amino acid, which means that it is biosynthesized in humans. Its codons are UGU and UGC. The side chain on cysteine is thiol, which is polar and thus cysteine is usually classified as a hydrophilic amino acid...
-rich module, called a T-knot scaffold, that is shared by several different protein families, including the EGF
Epidermal growth factor
Epidermal growth factor or EGF is a growth factor that plays an important role in the regulation of cell growth, proliferation, and differentiation by binding to its receptor EGFR...
family.
Medicinal properties
Because of the structural similarities with EGF, PCI inhibits tumor cell growth. Mechanism of actionMechanism of action
In pharmacology, the term mechanism of action refers to the specific biochemical interaction through which a drug substance produces its pharmacological effect...
is inhibition of receptor dimerization and receptor trans-autophosphorylation
Phosphorylation
Phosphorylation is the addition of a phosphate group to a protein or other organic molecule. Phosphorylation activates or deactivates many protein enzymes....
induced by epidermal growth factor (EGF). PCI blocks the formation and activation of ErbB1
Epidermal growth factor receptor
The epidermal growth factor receptor is the cell-surface receptor for members of the epidermal growth factor family of extracellular protein ligands...
/ErbB-2 (EGFR and HER2) heterodimers that have a prominent role in carcinoma
Carcinoma
Carcinoma is the medical term for the most common type of cancer occurring in humans. Put simply, a carcinoma is a cancer that begins in a tissue that lines the inner or outer surfaces of the body, and that generally arises from cells originating in the endodermal or ectodermal germ layer during...
development.PCI also inhibits transforming growth factor alpha (TGF-alpha).
In addition for pancreatic enzymes carboxypeptidase A
Carboxypeptidase A
Carboxypeptidase A usually refers to the pancreatic exopeptidase which hydrolyzes peptide bonds of C-terminal residues with aromatic or aliphatic side chains...
and B, PCI also inhibits carboxypeptidase R without affecting the activity of carboxypeptidase N in the circulation and have therefore use in thrombolytic therapy (blood clot lysis).
See also
Scaffold (disambiguation)Scaffold (disambiguation)
Scaffold and scaffolding may refer to:*Instructional scaffolding, the provision of sufficient supports to promote learning when concepts and skills are being first introduced to students...
Protein kinase
Protein kinase
A protein kinase is a kinase enzyme that modifies other proteins by chemically adding phosphate groups to them . Phosphorylation usually results in a functional change of the target protein by changing enzyme activity, cellular location, or association with other proteins...
Chemotherapy
Chemotherapy
Chemotherapy is the treatment of cancer with an antineoplastic drug or with a combination of such drugs into a standardized treatment regimen....
Thrombolysis
Thrombolysis
Thrombolysis is the breakdown of blood clots by pharmacological means. It is colloquially referred to as clot busting for this reason...
Cancer research
Cancer research
Cancer research is basic research into cancer in order to identify causes and develop strategies for prevention, diagnosis, treatments and cure....