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Matrix metalloproteinases are a family of zinc and calcium-dependent endopeptidases that break down extracellular matrix proteins. The MMP9 is secreted as a 92kDa zymogen. Cleavage of ProMMP-9 results in the active enzyme, having a molecular weight of approximately 82kDa. MMP9 is composed of the following domains: a gelatin-binding domain consisting of three fibronectin type II units, a catalytic domain containing the zinc-binding site, a proline-rich type V collagen-homologous domain and a hemopexin-like domain. MMP9 is produced by the several cell types: monocytes, macrophages, neutrophils, keratinocytes, fibroblasts, osteoclasts and endothelial cells. MMP9 is involved in inflammatory responses, tissue remodeling, wound healing, tumor growth and metastasis. MMP9 may also play an important part in local proteolysis of the extracellular matrix and in leukocyte migration, as well as in bone osteoclastic resorption. MMP9 cleaves type IV and type V collagens into large C-terminal three quarter fragments and shorter N-terminal one quarter fragments. MMP9 can also degrade fibronectin but not laminin or Pz-peptide.
MMP9 defects may be a cause of susceptibility to intervertebral disc disease (IDD), also known as lumbar disk herniation (LDH).

Complement Factor D (Adipsin), which belongs to the trypsin family of peptidases, is involved in the alternative complement pathway of the complement system where it cleaves factor B. In the alternative complement pathway, Adipsin is best known for its role in humoral suppression of infectious agents. In addition, Adipsin is a serine protease which is secreted by adipocytes into the bloodstream. Ultimately, Adipsin has a high level of expression in fat, proposing a role for adipose tissue in immune system biology.

Sirtuin-1 (SIRT1) belongs to the sirtuin family of proteins, homologs to the yeast Sir2 protein. Sirtuin family members are characterized by a sirtuin core domain and grouped into 4 classes. The functions of human sirtuins have not yet been established; though, yeast sirtuin proteins are known to regulate epigenetic gene silencing and suppress recombination of rDNA. It has been proposed that the human sirtuins may serve as intracellular regulatory proteins with mono-ADP-ribosyltransferase activity.

Actin depolymerizing factor (Destrin/DSTN) belongs to the ADF/Cofilin/destrin superfamily which has the ability to swiftly depolymerize F-Actin in a stoichiometric mode. The ADF family of proteins is responsible for enhancing the turnover rate of actin in vivo. Destrin is a small phosphoinositide-sensitive actin-binding protein capable of depolymerizing actin-filaments in vitro. DSTN functions in a pH-independent manner. DSTN is found in a variety of epithelial and endothelial cells, however it is virtually nonexistent in adult mouse heart and skeletal muscle cells. Destrin shares a 71% sequence homology with Cofilin, however the 2 proteins vary in their interaction with Actin.

a-Synuclein (amino acids 1-140), an acidic neuronal protein of 140 amino acids, is extremely heat-resistant and is natively unfolded with an extended structure primarily composed of random coils. a-synuclein has been suggested to be implicated in the pathogenesis of Parkinson’s disease and related neurodegenerative disorders, and more recently, to be an important regulatory component of vesicular transport in neuronal cells. Moreover, recent studies have shown that a-synuclein has chaperone activity and that this activity is lost upon removing its C-terminal acidic tail (amino acids 96-140).

Opticin also known as OPTC is a member of the class III of the small leucine-rich repeat protein (SLRP) family. Members of this family are usually linked with the extracellular matrix. OPTC is attended in significant quantities in the vitreous of the eye and also localizes to the cornea, iris, ciliary body, optic nerve, choroid, retina, and fetal liver. OPTC might noncovalently bind collagen fibrils and regulate fibril morphology, spacing and organization. OPTC is mapped to a an area of chromosome 1 which is linked with the inherited eye diseases age-related macular degeneration (AMD) and posterior column ataxia with retinosa pigmentosa (AXPC1).

Translational activator of mitochondrially encoded cytochrome c oxidase I (TACO1) belongs to the TACO1 family. TACO1 is a mitochondrial protein which functions as a translational activator of mitochondrially-encoded cytochrome c oxidase 1. Mutations in this gene are associated with Leigh syndrome.

Transgelin 2 (TAGLN2) is one of the earliest markers of differentiated smooth muscle. TAGLN2 contains a calponin like repeat and a calponin-homology (CH) domain. TAGLN2 is downregulated in some transformed cell lines, indicating that a reduction of transgelin expression may be an early indicator of the onset of transformation. TAGLN2 also binds actin, causing actin fibers to gel within minutes of binding. The binding of transgelin to actin occurs at a ratio of 1:6 actin monomers.

CCS is vital for the integration of copper into SOD-1, and as a result is needed for its enzymatic activity. CCS inhibits copper ions from binding to intracellular copper scavengers and provides the SOD-1 enzyme with the required copper cofactor. CCS escorts copper just to SOD-1 and is unable to deliver copper to proteins in the mitochondria, nucleus or secretory pathway. Although many tissues express CCS, the chaperone is most abundant in the kidney, liver and Purkinje cells in the neuropil of the central nervous system.

Recombinant Human Cytokeratin 20 His Tag (KRT20) belongs to the keratin family. The keratins are intermediate filament proteins responsible for the structural integrity of epithelial cells and are subdivided into cytokeratins and hair keratins. The type I cytokeratins is comprised of acidic proteins that are organized in pairs of heterotypic keratin chains. KRT20 is a main cellular protein of mature enterocytes and goblet cells and is specifically expressed in the gastric and intestinal mucosa.

Eosinophil lysophospholipase (CLC) acts on biological membranes to regulate the multifunctional lysophospholipids. CLC is a lysophospholipase expressed in eosinophils and basophils. CLC hydrolyzes lysophosphatidylcholine to glycerophosphocholine and a free fatty acid. The CLC protein may possess carbohydrate or IgE-binding activities. CLC is both structurally and functionally related to the galectin family of beta-galactoside binding proteins. CLC may be linked with inflammation and some myeloid leukemias.

Lumican also known as LUM belongs to the small leucine-rich proteoglycan (SLRP) family which comprises decorin, biglycan, fibromodulin, keratocan, epiphycan, and osteoglycin. Furthermore we can see that in these bifunctional molecules, the protein moiety binds collagen fibrils and the highly charged hydrophilic glycosaminoglycans regulate interfibrillar spacings. Lumican is the main keratan sulfate proteoglycan of the cornea however LUM is also distributed in interstitial collagenous matrices throughout the body. Lumican regulates collagen fibril organization and circumferential growth, corneal transparency, epithelial cell migration and tissue repair. Among the diseases associated with LUM is posterior amorphous corneal dystrophy.

Gankyrin (proteasome 26S subunit) is a multicatalytic proteinase oncoprotein commonly overexpressed in most hepatocellular carcinomas. Proteasomes are found throughout eukaryotic cells at a high concentrations and cleave peptides in an ATP/ubiquitin-dependent process in a non-lysosomal pathway. Gankyrin interacts with S6 ATPase of the 19S regulatory particle of the 26S proteasome. Gankyrin is involved in theregulation of the phosphorylation of the retinoblastoma protein by CDK4, and to enhance the ubiquitinylation of p53 by MDM2. Gankyrin consists of 7 ankyrin repeats and is structurally similar to I kappa Bs. Gankyrin acts as a regulatory subunit of the 26s proteasome which is involved in the atp-dependent degradation of ubiquitinated proteins. Gankyrin is involved in progression of esophageal squamous cell carcinoma. gankyrin plays an oncogenic role especially in early stages of human epatocarcinogenesis. Gankyrin binds to NF-kappaB and suppresses its activity at the transcription level by modulating acetylation through SIRT1. Structural comparison between Gankyrin & p16(INK4A) identified numerous residues of gankyrin that are potentially important for CDK4 binding.

The 26S proteasome is a multicatalytic proteinase complex with a well ordered structure composed of two complexes- a 20S core and a 19S regulator. PSMD11 is a non-ATPase subunit of the 19S regulator. The 20S core is composed of four rings of 28 non-identical subunits; two rings are composed of 7 alpha subunits and two rings are composed of 7 beta subunits. The 19S regulator is composed of a base that contains six ATPase subunits and two non-ATPase subunits, and a lid that contains up to ten non-ATPase subunits. Proteasomes are spread throughout eukaryotic cells at a high concentration and cleave peptides in an ATP/ubiquitin-dependent process in a non-lysosomal pathway. An indispensable function of a modified proteasome, the immunoproteasome, is the processing of class I MHC peptides.

HSP10 is part of the molecular chaperons, that are crucial for thir efficient folding of proteins in normal as well as stress conditions. GroES function is to bind to HSP60 in the presence of ATP, thus causing a change in the HSP60 conformation & enclosing the protein substrate within the complex. ATP hydrolysis by chaperonin-60 which destabilizes the HSP10-HSP60 complex, thereby allowing it to dissociate and secrete the substrate protein.
GroES having the NCBI accession number of NP_002148 was purified by using conventional chromatography techniques.

GSTK1 is involved in cellular detoxification. GSTK1 is localized to the peroxisome and catalyzes the conjugation of the thiol group of glutathione (GSH) to the electrophilic groups of a broad range of hydrophobic substrates, leading to an easier removal of the latter from the cells.

CRABP2 NCBI Accession No: NP_001869 regulates the access of retinoic acid to the nuclear retinoic acid receptors. CRABP2 is involved in a regulatory feedback mechanism that controls the action of retinoic acid on cell differentiation.
CRABP2 is involved in the conversion of vitamin A into its intracellular active form retinoic acid, which regulate the genes responsible for lipid metabolism and adipocyte differentiation. CRABP2 gene is located on chromosome 1q21-23 and this region has been linked with related disorders such as familial combined hyperlipidemia (FCHL) and type 2 diabetes mellitus.
CRABP proteins are of low molecular weight having an important function in retinoic acid-mediated regulation of human skin growth and differentiation.

RELM-gamma is a novel member of the resistin-like molecule/found in inflammatory zone (RELM/FIZZ) family in mice and rats. Microarray and real-time RT-PCR experiments revealed a repression of RELMgamma mRNA in nasal respiratory epithelium of cigarette smoke-exposed versus untreated rats. The analysis of the physiological tissue-specific expression revealed highest expression in hematopoietic tissues, suggesting a cytokine-like role for RELM-gamma. RELM-gamma-mRNA is detectable in bone marrow, spleen, and lung as well as in peripheral blood granulocytes. Promyelocytic HL60 cells transfected with a RELM-gamma expression plasmid have an increased proliferation rate compared to mock-transfected cells and display an altered response to retinoic acid-induced granulocytic differentiation. Taken together, these data provide the first experimental evidence that RELM-gamma is a secreted molecule with a restricted expression pattern that may play a role in promyelocytic differentiation.

BLNK is a cytoplasmic linker or adaptor protein which has a significant role in B cell development. B-cell linker (BLNK) is essential for normal B-cell development. BLNK bridges B cell receptor-associated kinase activation with downstream signaling pathways, thus affecting different biological functions. BLNK associates with the effector proteins GRB2, Vav, NCK and PLC-g following activation of the B cell receptor. BLNK is phosphorylated by the Syk tyrosine kinase, which in turn permits activation of downstream effector proteins including GRB2 and PLC-g. Mutations in the BLNK gene cause hypoglobulinemia and absent B cells, a disease in which the pro- to pre-B-cell transition is developmentally blocked. Deficiency in the BLNK protein is seen in some cases of pre-B acute lymphoblastic leukemia.

Persephin is a member of the GDNF ligand subfamily of the TGF-beta superfamily. PSPN encourages the existence and growth of key dopaminergic and motor neurons, as well as taking part in kidney development. Nonetheless, persephin does not support existence of peripheral neurons.

GST family of enzymes comprises a long list of cytosolic, mitochondrial, and microsomal proteins that are 45-55 kDa (dimer form) size and are capable of multiple reactions with a multitude of substrates, both endogenous and xenobiotic. GST catalyses the conjugation of reduced glutathione meaning the sulfhydryl group, to electrophilic centers on a wide variety of substrates. This activity is useful in the detoxification of endogenous compounds such as peroxidised lipids, as well as the metabolism of xenobiotics. GST binds toxins and function as transport protein. Glutathione S-transferase is used to create the so-called ''GST gene fusion system''. The GST is used to purify and detect proteins of interest. In a GST gene fusion system, the GST sequence is incorporated into an expression vector alongside the gene sequence encoding the protein of interest. Induction of protein expression from the vector''s multiple cloning sites results in expression of a fusion protein - the protein of int

Plasma fibronectin level is elevated in severe coronary artery disease. Increased plasma fibronectin levels are related with venous thromboembolism (VTE) particularly in males, and extend the probable association between biomarkers and risk factors for arterial atherothrombosis and VTE. Fibronectin plays a role in several cellular processes, including tissue repair, embryogenesis, blood clotting, and cell migration/adhesion. Fibronectin consists in two main forms: 1) as an insoluble glycoprotein dimer that serves as a linker in the extracellular matrix and 2) as a soluble disulphide linked dimer found in the plasma. The plasma form is produced by hepatocytes, and the ECM form is synthesized by fibroblasts, chondrocytes, endothelial cells, macrophages, as well as certain epithelial cells. Fibronectin also takes part as a general cell adhesion molecule by anchoring cells to collagen or proteoglycan substrates. Fibronectin organizes cellular interaction with the ECM by binding to different components of the extracellular matrix and to membrane-bound Fibronectin receptors on cell surfaces.

Serpin Peptidase Inhibitor, Clade A Member 9, also known as serpin A9, belongs to the Serpin superfamily of serine protease inhibitors. Serpins are the most extensively distributed superfamily of protease inhibitors which use a conformational modification to inhibit target enzymes. Serpins are known to inhibit serine proteases as well as inhibiting caspases in addition to papain-like cysteine proteases. Serpins are conformational labile and numerous of the disease-linked mutations of serpins outcome in misfolding or in pathogenic, inactive polymers. serpin A9 demonstrates inhibition towards trypsin, thrombin, as well as plasmin and binds DNA and heparin.