Cystatin

Cystatin C is part to the cystatin protein family, which has members with various cystatin-like sequences. Part of the proteins has the ability to act as active cysteine protease inhibitors, other members has lost or never had the ability. Three sub members of the cystatin protein family are the type 1 cystatins, type 2 cystatins & kininogens. The locus in chromosome twenty holds the most type 2 cystatin genes. Cystatin C can be found in the cystatin locus, it is the most common extracellular inhibitor of cysteine proteases, that is available in big volumes in biological fluids and exist in every tissue in the body.

Cystatins are a superfamily of cysteine proteinase inhibitors found in both plants and animals. They comprise a group of proteinase inhibitors, widely distributed in tissues and body fluids, and form tight complexes with cysteine proteases such as cathepsin B, H, L and S. Cystatin C, a secreted molecule of this family, is of interest from biochemical, medicine and evolutionary points of view. Cystatin C, with molecular weight of 13260 Da, is composed of 120 amino acids, lacks carbohydrate and has two disulfide bridges located near the carboxyl terminus. Cystatin C is increased in patients with malignant diseases, and is related to the insufficiency of renal function and appears to be a better marker than creatinine. On the other hand, low levels of cystatin C involve cause the breakdown of the elastic laminae and, subsequently, the atherosclerosis and abdominal aortic aneurysm.

Cystatins are a superfamily of cysteine proteinase inhibitors found in both plants and animals. They comprise a group of proteinase inhibitors, widely distributed in tissues and body fluids, and form tight complexes with cysteine proteases such as cathepsin B, H, L and S. Cystatin C, a secreted molecule of this family, is of interest from biochemical, medicine and evolutionary points of view. Cystatin C is increased in patients with malignant diseases, and is related to the insufficiency of renal function and appears to be a better marker than creatinine. On the other hand, low levels of cystatin C involve cause the breakdown of the elastic laminae and subsequently, the atherosclerosis and abdominal aortic aneurysm.

Cystatin B or CSTB, is an protein (anti-protease) that is suspected to be involved in myoclonus epilepsy. As part of the encompasses proteins family, it has many cystatin-like sequences. Part of the cystatin superfamily are cysteine protease inhibitors; part don’t have the ability. CSTB can create a dimer that is stable because of noncovalent bonds and has a crucial part in shielding from lysosomal proteases leaking. Cystatin B can be found in the lysosomes, nucleus & the cytoplasm in cells.

Type 1 cystatins are also called stefins which function as intracellular thiol protease inhibitors. Cystatin-B protein is able to form a dimer stabilized by noncovalent forces, inhibiting papain and cathepsins l, h and b. CSTB protein protects proteases leakage from lysosomes. Mutations in Stefin-B gene cause primary defects in patients with progressive myoclonic epilepsy (EPM1), a degenerative disease of the central nervous system. CSTB is overexpressed & elevated in the serum of HCC patients. Cystatin-B in vivo has a polymeric structure which is sensitive to the redox environment. Cystatin-B inhibits bone resorption by down-regulating intracellular cathepsin K activity despite increased osteoclast survival. Protein and mRNA levels of stefin B are significantly lower in atypical benign meningiomas. Stefins-A & Stefin-B which belong to the type-1 Cystatins, are up-regulated in lung tumours and thus able to counteract harmful tumour-associated proteolytic activity. Human stefin-A & Stefin-B form amyloid fibrils. Copper binding by stefin-B reduces amyloid fibril formation. A number of alternatively spliced CSTB isoforms were recognized in patients with progressive myoclonus epilepsy. Decreased CSTB activity in EPM1 pathogenesis is controled by cathepsins through increased activity of cathepsin-S & cathepsin-L.

Cystatin-A is the intracellular inhibitor of cysteine proteinase cathepsin B (CatB) and belongs to family 1 of the cystatin superfamily of inhibitor proteins. CSTA is a stefin that functions as a cysteine protease inhibitor, forming tight complexes with papain and the cathepsins B, H, and L. It has been proposed that extracellular CatB together with other classes of proteinases are all subjected to a cascade-like manner of activation. CatB and its inhibitor Cystatin-A are involved in degradation of extracellular matrix proteins during tissue remodeling. CSTA is one of the precursor proteins of cornified cell envelope in keratinocytes and plays a role in epidermal development and maintenance. Cystatin-A has been reported to be found in high concentrations in epithelial cells, polymorphonuclear leukocytes and lymphoid tissue. Stefins may be used as prognostic and diagnostic tools for cancer.

Human Cystatin A (CSTA or Stefin A) belongs to family 1 of the cystatin superfamily, which is characterized by the lack of disulphide bonds and carbohydrates. CSTA is an intracellular inhibitor regulating the activities of cysteine proteases of the papain family such as Cathepsins B, H and L. Cystatin A has also been implicated in several disease states. Because of altered proteolytic state in cancer progression, CSTA may have a role in the proteolitic pathways.

CST9 belongs to the CRES (cystatin-related epididymal spermatogenic) subfamily. The CRES (cystatin-related epididymal spermatogenic) protein outlines a new subgroup in the family 2 cystatins of the cystatin superfamily. A few members are active cysteine protease inhibitors, however others have lost or possibly never developed this inhibitory activity. CST9 takes part in hematopoietic differentiation or inflammation and is expressed in heart, placenta, lung, liver, skeletal muscle and pancreas. CST9 is upregulated by LPS in several cancer cell lines, such as promyelocytic leukemia (HL-60) and myelomonocytic leukemia.

Cystatin 7 (CST7) is a glycosylated cysteine protease inhibitor with a putative role in immune regulation through inhibition of a unique target in the hematopoietic system. Cystatin-7 is comprised of multiple cystatin-like sequences. The superfamily is comprised of 3 inhibitory families: the type 1 cystatins (stefins), type 2 cystatins and the kininogens. Some members are active cysteine protease inhibitors, while others have lost or possibly never had this inhibitory activity. Type 2 cystatin proteins are a class of cysteine proteinase inhibitors found in various human fluids and secretions. CST7 protein expression has been observed in numerous human cancer cell lines established from malignant tumors.

Cystatin E/M or CST6 is part of the cystatin type 2 family. Part of the cystatin type 2 family members can act as cysteine protease inhibitors, whereas cystatin E/M regulates cathepsin B inhibitors and not cathepsin C. cystatin E/M is a protein the when secreted, has an effect on osteogenesis and bone resorption, insulin regulation, response to systemic inflammation & hepatocyte growth factor receptors.

CST6 belongs to the type 2 cystatin family. Unlike other family members that act as active cysteine protease inhibitors, CST6 restrain the inhibition of cathepsin B but is not active against cathepsin C. CST6 are secretable proteins that influence osteogenesis and bone resorption, regulation of the hepatocyte growth factor receptors, and the response to systemic inflammation.

Cystatin 5 (CST5) is a novel member of the cystatin superfamily, which encompasses proteins that contain multiple cystatin-like sequences. Some members are active cysteine protease inhibitors, while others have lost or possibly never had this inhibitory activity. The superfamily is comprised of 3 inhibitory families: the type 1 cystatins (stefins), type 2 cystatins and the kininogens. Type 2 cystatin proteins are a class of cysteine proteinase inhibitors found in various human fluids and secretions.

CST4 is a member of the cystatin superfamily which contains proteins that hold multiple cystatin-like sequences. Several family members are active cysteine protease inhibitors, whereas others have lost or possibly never attained this inhibitory activity. CST4 strongly inhibits papain (non-competitively) and ficin, partially inhibits stem bromelain and bovine cathepsin C, however does not inhibit porcine cathepsin B or clostripain.

CST4 is a member of the cystatin superfamily which contains proteins that hold multiple cystatin-like sequences. Several family members are active cysteine protease inhibitors, whereas others have lost or possibly never attained this inhibitory activity. CST4 strongly inhibits papain (non-competitively) and ficin, partially inhibits stem bromelain and bovine cathepsin C, however does not inhibit porcine cathepsin B or clostripain.

Cystatins are a superfamily of cysteine proteinase inhibitors found in both plants and animals. They comprise a group of proteinase inhibitors, widely distributed in tissues and body fluids, and form tight complexes with cysteine proteases such as cathepsin B, H, L and S. Cystatin C, a secreted molecule of this family, is of interest from biochemical, medicine and evolutionary points of view. Cystatin C, with molecular weight of 13260 Da, is composed of 120 amino acids, lacks carbohydrate and has two disulfide bridges located near the carboxyl terminus. Cystatin C is increased in patients with malignant diseases, and is related to the insufficiency of renal function and appears to be a better marker than creatinine. On the other hand, low levels of cystatin C involve cause the breakdown of the elastic laminae and, subsequently, the atherosclerosis and abdominal aortic aneurysm.

Cystatins are a superfamily of cysteine proteinase inhibitors found in both plants and animals. They comprise a group of proteinase inhibitors, widely distributed in tissues and body fluids, and form tight complexes with cysteine proteases such as cathepsin B, H, L and S. Cystatin C, a secreted molecule of this family, is of interest from biochemical, medicine and evolutionary points of view. Cystatin C, with molecular weight of 13260 Da, is composed of 120 amino acids, lacks carbohydrate and has two disulfide bridges located near the carboxyl terminus. Cystatin C is increased in patients with malignant diseases, and is related to the insufficiency of renal function and appears to be a better marker than creatinine. On the other hand, low levels of cystatin C involve cause the breakdown of the elastic laminae and, subsequently, the atherosclerosis and abdominal aortic aneurysm.

Cystatins are a superfamily of cysteine proteinase inhibitors found in both plants and animals. They comprise a group of proteinase inhibitors, widely distributed in tissues and body fluids, and form tight complexes with cysteine proteases such as cathepsin B, H, L and S. Cystatin C, a secreted molecule of this family, is of interest from biochemical, medicine and evolutionary points of view. Cystatin C, with molecular weight of 13260 Da, is composed of 120 amino acids, lacks carbohydrate and has two disulfide bridges located near the carboxyl terminus. Cystatin C is increased in patients with malignant diseases, and is related to the insufficiency of renal function and appears to be a better marker than creatinine. On the other hand, low levels of cystatin C involve cause the breakdown of the elastic laminae and, subsequently, the atherosclerosis and abdominal aortic aneurysm.

Cystatins are a superfamily of cysteine proteinase inhibitors found in both plants and animals. They comprise a group of proteinase inhibitors, widely distributed in tissues and body fluids, and form tight complexes with cysteine proteases such as cathepsin B, H, L and S. Cystatin C, a secreted molecule of this family, is of interest from biochemical, medicine and evolutionary points of view. Cystatin C, with molecular weight of 13260 Da, is composed of 120 amino acids, lacks carbohydrate and has two disulfide bridges located near the carboxyl terminus. Cystatin C is increased in patients with malignant diseases, and is related to the insufficiency of renal function and appears to be a better marker than creatinine. On the other hand, low levels of cystatin C involve cause the breakdown of the elastic laminae and, subsequently, the atherosclerosis and abdominal aortic aneurysm.

Cystatins are a superfamily of cysteine proteinase inhibitors found in both plants and animals. They comprise a group of proteinase inhibitors, widely distributed in tissues and body fluids, and form tight complexes with cysteine proteases such as cathepsin B, H, L and S. Cystatin C, a secreted molecule of this family, is of interest from biochemical, medicine and evolutionary points of view. Cystatin C, with molecular weight of 13260 Da, is composed of 120 amino acids, lacks carbohydrate and has two disulfide bridges located near the carboxyl terminus. Cystatin C is increased in patients with malignant diseases, and is related to the insufficiency of renal function and appears to be a better marker than creatinine. On the other hand, low levels of cystatin C involve cause the breakdown of the elastic laminae and, subsequently, the atherosclerosis and abdominal aortic aneurysm.

Cystatins are a superfamily of cysteine proteinase inhibitors found in both plants and animals. They comprise a group of proteinase inhibitors, widely distributed in tissues and body fluids, and form tight complexes with cysteine proteases such as cathepsin B, H, L and S. Cystatin C, a secreted molecule of this family, is of interest from biochemical, medicine and evolutionary points of view. Cystatin C, with molecular weight of 13260 Da, is composed of 120 amino acids, lacks carbohydrate and has two disulfide bridges located near the carboxyl terminus. Cystatin C is increased in patients with malignant diseases, and is related to the insufficiency of renal function and appears to be a better marker than creatinine. On the other hand, low levels of cystatin C involve cause the breakdown of the elastic laminae and, subsequently, the atherosclerosis and abdominal aortic aneurysm.

Cystatins are a superfamily of cysteine proteinase inhibitors found in both plants and animals. They comprise a group of proteinase inhibitors, widely distributed in tissues and body fluids, and form tight complexes with cysteine proteases such as cathepsin B, H, L and S. Cystatin C, a secreted molecule of this family, is of interest from biochemical, medicine and evolutionary points of view. Cystatin C, with molecular weight of 13260 Da, is composed of 120 amino acids, lacks carbohydrate and has two disulfide bridges located near the carboxyl terminus. Cystatin C is increased in patients with malignant diseases, and is related to the insufficiency of renal function and appears to be a better marker than creatinine. On the other hand, low levels of cystatin C involve cause the breakdown of the elastic laminae and, subsequently, the atherosclerosis and abdominal aortic aneurysm.

Cystatins are a superfamily of cysteine proteinase inhibitors found in both plants and animals. They comprise a group of proteinase inhibitors, widely distributed in tissues and body fluids, and form tight complexes with cysteine proteases such as cathepsin B, H, L and S. Cystatin C, a secreted molecule of this family, is of interest from biochemical, medicine and evolutionary points of view. Cystatin C is increased in patients with malignant diseases, and is related to the insufficiency of renal function and appears to be a better marker than creatinine. On the other hand, low levels of cystatin C involve cause the breakdown of the elastic laminae and subsequently, the atherosclerosis and abdominal aortic aneurysm.

Cystatin 11 (CST11) is a member of the Cystatin family. The Cystatin superfamily is comprised of proteins with multiple cystatin-like sequences. Several family members are active cysteine protease inhibitors, other family members have lost or perhaps never developed this inhibitory activity. The Cystatin superfamily consists of three inhibitory families, including the type 1 cystatins (stefins), type 2 cystatins and the kininogens. The type 2 cystatin proteins are a class of cysteine proteinase inhibitors found in a variety of human fluids and secretions. The majority of the type 2 cystatin genes and pseudogenes are contained in the cystatin locus on chromosome 20. CST11 is located in the cystatin locus and encodes an epididymal-specific protein whose specific function has not been verified yet.

Cystatin-SN (CST1) belongs to the type 2 salivary cystatin family found in a variety of fluids and secretions, including plasma, tears, and saliva. The cystatin superfamily includes proteins which contain multiple cystatin-like sequences. Some of the members are active cysteine protease inhibitors, whereas others have lost or possibly never developed this inhibitory activity. CST1 is up-regulated in cancerous lesions of gastric cancer tissues compared to noncancerous regions, in addition clinicopathological analysis revealed a significant correlation between high expression of CST1.