ELISA

Cystatin B(CSTB), also called STFB, is a small protein that is a member of the superfamily of cysteine protease inhibitors. It has been isolated from human spleen and liver and its amino acid sequence has been fully determined. The cystatin B gene is located on 21q22.3. It is widely distributed and is localized mostly intracellularly, but has been found extracellularly. The protein is able to form a dimer stabilized by noncovalent forces, inhibiting papain and cathepsins l, h and b. Its role is thought to be as a protector against the proteinases leaking from lysosomes. A cystatin B multiprotein complex might have a specific cerebellar function, and that the loss of this function might contribute to the etiopathogenesis of EPM1. Upon differentiation to myotubes, CSTB becomes excluded from the nucleus and lysosomes, suggesting that the subcellular distribution of CSTB is dependent on the differentiation status of the cell.

Thymic stromal lymphopoietin, also called TSLP, is a protein belonging to the cytokine family. This gene is mapped to 5q22.1. It encodes a hemopoietic cytokine proposed to signal through a heterodimeric receptor complex composed of the thymic stromal lymphopoietin receptor and the IL-7R alpha chain. It mainly impacts myeloid cells and induces the release of T cell-attracting chemokines from monocytes and enhances the maturation of CD11c(+) dendritic cells. The protein promotes T helper type 2(TH2) cell responses that are associated with immunity in various inflammatory diseases, including asthma, allergic inflammation and chronic obstructive pulmonary disease. The protein is therefore considered a potential therapeutic target for the treatment of such diseases.

Beta-microseminoprotein, also known as MSMB or PSP94, is a protein that in humans is encoded by the MSMB gene. It is a member of the immunoglobulin binding factor family. This gene is mapped to 10q11.23. It is synthesized by the epithelial cells of the prostate gland and secreted into the seminal plasma. The expression of the encoded protein is found to be decreased in prostate cancer. But transcripts of identical size were found in prostate, respiratory(tracheal, bronchial, and lung) tissues, and the mucosa of the gastric antrum. Thus, the protein may have functions other than those related to male reproduction. This protein has inhibin-like activity. It may have a role as an autocrine paracrine factor in uterine, breast and other female reproductive tissues.

Amyloid P component, serum(SAP), also known as PTX2 or APCS, is the identical serum form of amyloid P component(AP), a 25kDa pentameric protein first identified as the pentagonal constituent of in vivo pathological deposits called "amyloid". It belongs to the pentraxins family, characterized by calcium dependent ligand binding and distinctive flattened beta-jellyroll structure similar to that of the legume lectins. This gene is mapped to 1q23.2. The binding of the encoded protein to proteins in the pathological amyloid cross-beta fold suggests its possible role as a chaperone. This protein is also thought to control the degradation of chromatin. It has been demonstrated that this protein binds to apoptotic cells at an early stage, which raises the possibility that it is involved in dealing with apoptotic cells in vivo.

Amyloid P component, serum(SAP), also known as PTX2 or APCS, is the identical serum form of amyloid P component(AP), a 25kDa pentameric protein first identified as the pentagonal constituent of in vivo pathological deposits called "amyloid". It belongs to the pentraxins family, characterized by calcium dependent ligand binding and distinctive flattened beta-jellyroll structure similar to that of the legume lectins. This gene is mapped to 1q23.2. The binding of the encoded protein to proteins in the pathological amyloid cross-beta fold suggests its possible role as a chaperone. This protein is also thought to control the degradation of chromatin. It has been demonstrated that this protein binds to apoptotic cells at an early stage, which raises the possibility that it is involved in dealing with apoptotic cells in vivo.

SPARC(secreted protein acidic and rich in cysteine), also known as Osteonectin, is a protein that in humans is encoded by the SPARC gene. The human SPARC gene is 26.5 kb long, and contains 10 exons and 9 introns and is located on chromosome 5q31-q33. SPARC is a glycoprotein of 40 kD. SPARC is an acidic, cysteine-rich glycoprotein consisting of a single polypeptide chain that can be broken into 4 domains: 1) an Ca++ binding domains near the glutamic acidic-rich region at the amino terminus(domain I), 2) a cysteine- rich(domain II), 3) a hydrophilic region(domain III) and 4) an EF hand motif at the carboxy terminus region(domain IV). Osteonectin is a glycoprotein in the bone that binds sodium. It is secreted by osteoblasts during bone formation, initiating mineralization and promoting mineral crystal formation. Osteonectin also shows affinity for collagen in addition to bone mineral calcium. A correlation between osteonectin over expression and ampullary cancers and chronic pancreatitis

The urokinase-type plasminogen activator receptor(uPAR) is a key molecule in the regulation of cell-surface plasminogen activation and, as such, plays an important role in many normal as well as pathological processes.1 The cDNA for Mo3, an activation antigen expressed by human monocytes and myelomonocytic cell lines after stimulation by a variety of agents. Mo3 expression in vivo is associated predominantly with macrophages in inflammatory sites. It is a highly glycosylated protein of about 50 kD in monocytes where it is anchored to the plasma membrane by glycosyl-phosphatidylinositol linkage. The complete coding sequence of the cDNA has been found to encode 419 amino acids including a predicted signal peptide of 22 residues and a hydrophobic C-terminal portion. Mo3 is identical to the human receptor for the urokinase plasminogen activator.2 UPAR is a useful prognostic marker for biologically aggressive forms of endometrial cancer.3 PLAUR is located at chromosome 19q13.1-q13.2.1

Alanine aminopeptidase, also known as ANPEP or CD13. is an enzyme that is used as a biomarker to detect damage to the kidneys, and that may be used to help diagnose certain kidney disorders. It is mapped to 15q26.1. Aminopeptidase N is located in the small-intestinal and renal microvillar membrane, and also in other plasma membranes. In the small intestine, Aminopeptidase N plays a role in the final digestion of peptides generated from hydrolysis of proteins by gastric and pancreatic proteases, and it is also thought to be involved in the metabolism of regulatory peptides by diverse cell types, including small intestinal and renal tubular epithelial cells, macrophages, granulocytes, and synaptic membranes from the CNS. Petrovic et al showed that CD13 was required for endothelial cell invasion in response to bradykinin. Inhibition of CD13 abrogated internalization of bradykinin receptor B2 and reduced endothelial cell motility.

Hepatocyte growth factor(HGF) is the most potent mitogen for mature parenchymal hepatocytes in primary culture, and seems to be a hepatotrophic factor that acts as a trigger for liver regeneration after partial hepatectomy and liver injury. HGF has a relative molecular mass(Mr) of 82,000 and is a heterodimer composed of a large alpha-subunit of Mr 69,000 and a small beta-subunit of Mr 34,000. The protein consists of 728 amino acid residues, including a possible signal peptide at the N-terminus. HGF may serve as a paracrine mediator to control placental development and growth. This growth factor may play an important role as a paracrine mediator of the proliferation of melanocytes and endothelial cells, as well as cells of epithelial origin. The gene encoding the human HGF is assigned to human chromosome 7.