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Streptavidin is a tetrameric protein secreted by Streptomyces avidinii which binds firmly to biotin. Streptavidin is widely used in molecular biology through its unique high affinity for the vitamin biotin. The dissociation constant (Kd) of the biotin-streptavidin complex is about ~10-15 mol/L. The strong affinity recognition of biotin and biotinylated molecules has made streptavidin one of the most important components in diagnostics and laboratory kits. The streptavidin/biotin system has one of the biggest free energies of association of yet observed for noncovalent binding of a protein and small ligand in aqueous solution (K_assoc = 10**14). The complexes are also extremely stable over a wide range of temperature and pH.

Since April 2012, cases of the Middle East Respiratory Syndrome Coronavirus (MERS-CoV) have been identified in various countries. Coronaviruses are the cause of the common cold, SARS (severe acute respiratory syndrome) and other severe illnesses with high mortality rates, all are classified into coronavirus family. MERS-CoV is a new type of SARS found in the coronavirus family causing severe pneumonia with sudden and serious respiratory illness with high mortality rates as well. Since January 27th 2015, the WHO has reported 956 human cases, including 351 deaths. More cases of the new coronavirus strain are expected. Like in other coronaviruses, large surface spike glycoprotein is a central structural protein of this virus; it is located above the virion surface to bind and enter into the target cell. Spike protein has 2 domains- S1 and S2. The S1 domain is responsible for cellular tropism and interaction with target cell, while the S2 domain is responsible for membrane fusion. The C-terminal of S1 domain contains a receptor binding domain, and is also a potential target for vaccine development and an antigen for diagnosis.

Caseine Kinase 1 alpha belongs is a member of the protein kinase superfamily, CK1 Ser/Thr protein kinase family, Casein kinase I subfamily. The CK1 isoforms - alpha, beta, gamma, delta, epsilon and their splice variants are involved in diverse cellular processes including membrane trafficking, circadian rhythm, cell cycle progression, chromosome segregation, apoptosis and cellular differentiation. Possibly CSNK1A1 can phosphorylate a large number of proteins and is involved in Wnt signaling where it phosphorylates CTNNB1 on Ser45. CSNK1A1 also interacts with the Axin complex.

ORF73 protein of human herpesvirus 8 is a Kaposi''s sarcoma-associated herpesvirus latent protein that is suspected of playing a critical role in modulating viral and cellular gene expression. ORF73 is linked to cellular chromatin and stays on the chromosomes during cell division. ORF73 maintains the viral genomes during cell division by tethering the viral episomes to the chromosomes. ORF73 binds directly to replication origin recognition complexes which are primarily connected with the terminal repeat region of the HHV8 genome.

Vaspin (visceral adipose-specific SERPIN), a newly identified adipokine, which is a member of serine protease inhibitor family. Vaspin is also a unique insulin sensitizing adipocytokine in obesity. A recent publication indicates that induction of human vaspin mRNA expression in adipose tissue is regulated in a fat depot-specific manner and could be associated with parameters of obesity, insulin resistance, and glucose metabolism.

4-1BBR is a member of the TNF-receptor superfamily. 4-1BB receptor contributes to the clonal expansion, survival, and development of T cells.4-1BBRcan also induce proliferation in peripheral monocytes, enhance T cell apoptosis induced by TCR/CD3 triggered activation, and regulate CD28 co-stimulation to promote Th1 cell responses. The expression of this receptor is induced by lymphocyte activation. TRAF adaptor proteins have been shown to bind to this receptor and transduce the signals leading to activation of NF-kappaB.

Acyl-CoA Thioesterase 8 (ACOT8) is a group of enzymes which catalyze the hydrolysis of acyl-CoAs to the free fatty acid and coenzyme A (CoASH), granting the potential to regulate intracellular levels of acyl-CoAs, free fatty acids and CoASH. ACOT8 mediate Nef-induced down-regulation of CD4. ACOT8 contends with BAAT (Bile acid CoA: amino acid N-acyltransferase) for bile acid-CoA substrate (such as chenodeoxycholoyl-CoA). ACOT8 prefers medium-length fatty acyl-CoAs.

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.

S100b is a member of the S100 family of proteins which are a family of EF-hand calcium binding proteins that exist mostly as dimers of the 20 currently identified individual S100 monomers. The S100B homodimer is expressed in cells of the central nervous system, glial cells and in certain peripheral cells e.g. Schwann cells, melanocytes, adipocytes and chondrocytes. S100 proteins are localized either in the cytoplasm or the nucleus of a wide range of cells. S100 proteins are involved in the regulation of a number of cellular processes such as cell cycle progression and differentiation. There are at least 13 members in the S100 gene family, which are located as a cluster on chromosome 1q21; however, S100b is located at 21q22.3. The determination of S100B in serum levels may be used to monitor the extent of brain injury and malignant melanoma. S100b proteins may have a role in Neurite extension, proliferation of melanoma cells, stimulation of Ca2+ fluxes, inhibition of PKC-mediated phosphorylation, astrocytosis and axonal proliferation, and inhibition of microtubule assembly. Chromosomal rearrangements and altered expression of the S100b gene are implicated in several neurological, neoplastic, and other types of diseases, including Alzheimer's disease, Down's syndrome, epilepsy, amyotrophic lateral sclerosis, melanoma, and type I diabetes.

Macrophage Inflammatory Proteins (MIP) belong to the family of chemotactic cytokines known as chemokines. In humans, there are two major forms, MIP-1? and MIP-1? that are now officially named CCL3 and CCL4 respectively. Both are major factors produced by macrophages after they are stimulated with bacterial endotoxins. They activate human granulocytes (neutrophils, eosinophils and basophils) which can lead to acute neutrophilic inflammation. They also induce the synthesis and release of other pro-inflammatory cytokines such as interleukin 1 (IL-1), IL-6 and TNF-? from fibroblasts and macrophages. The genes for CCL3 and CCL4 are both located on human chromosome 17.

Cathepsin F ( CTSF) is a member of the peptidase C1 family. Cathepsins are papain familycysteine proteinases which are a main component of the lysosomal proteolytic system. The CTSF gene isubiquitously expressed, and it maps to chromosome 11q13, close to the gene encoding cathepsin W. CTSF plays a role in normal protein catabolism. CTSF involved in some degradative processes occurring in tumor progression since it is highly expressed in some cancer cell lines.

Aspartylglucosaminidase, also known as AGA, takes part in the catabolism of Nlinked oligosaccharides of glycoproteins. AGA is a protein coding gene which cleaves asparagine from N-acetylglucosamines in the lysosomal breakdown of glycoproteins.

Osteostat is the cytokine that binds to TNFRSF18/AITR/GITR and is important for interactions between activated T-lymphocytes and endothelial cells and may modulate T-lymphocyte survival in peripheral tissues. Osteostat is expressed at high levels in the small intestine, ovary, testis, kidney and endothelial cells after stimulation by lipopolysaccharides.
Osteostat protein is detectable in human microvascular EC and is highly up-regulated by IFN-alpha and IFN-beta. Osteostat inhibit differentiation of osteoclasts from monocytic precursor cells. Osteostat suppresses the early stage of osteoclastogenesis via inhibition of macrophage colony-stimulating factorinduced receptor activator of NF-kappaB (RANK) expression in the osteoclast precursor cells. Osteostat does not inhibit lipopolysaccharide-induced RANK expression in monocytes and dendritic cells, or activation-induced RANK expression in T cells. Osteostat is a novel regulator of osteoclast generation and substantiate the major role played by the endothelium in bone physiology.

DCTN2 is a 50kDa subunit of dynactin, which is a macromolecular complex consisting of 10-11 subunits ranging in size from 22 to 150 kDa. Dynactin binds to both microtubules and cytoplasmic dynein. Dynactin is involved in a various cellular functions, including ER-to-Golgi transport, the centripetal movement of lysosomes and endosomes, spindle formation, chromosome movement, nuclear positioning, and axonogenesis. The DCTN2 subunit is present in 4-5 copies per dynactin molecule. DCTN2 is comprised of 3 short alpha-helical coiled-coil domains which mediate association with self or other dynactin subunits. DCTN2 interacts directly with the largest subunit (p150) of dynactin and is able to affix p150 in place. DCTN2 modulates cytoplasmic dynein binding to an organelle, and plays a part in prometaphase chromosome alignment and spindle organization during mitosis. DCTN2 is involved in anchoring microtubules to centrosomes. DCTN2 has a role in synapse formation during brain development.

DCN1-like protein 2 (DCUN1D2) which contains one DCUN1 domain and 1 UBA-like domain, may have a role in the neddylation of cullins which regulate SCF-type ubiquitin ligase complexes. The gene encoding Dcun1D2 is located on human chromosome 13. Chromosome 13 contains major tumor suppressor genes, including BRCA2 and RB1, which are linked with breast cancer susceptibility and retinoblastoma, respectively.

Anti-Mullerian Hormone also known as AMH is a member of the TGF-beta family. AMH is a glycoprotein which is produced by the Sertoli cells of the testis, causes regression of the Muellerian duct. AMH inhibits the growth of tumors derived from tissues of Muellerian duct origin. Moreover, AMH participates in Leydig cell differentiation and function in addition to follicular development in adult females.

HP-NAP protects DNA from oxidative damage by sequestering intracellular Fe2+ ion and storing it in the form of Fe3+ oxyhydroxide mineral. One hydrogen peroxide oxidizes two Fe2+ ions, thus preventing hydroxyl radical production by the Fenton reaction. HP-NAP is necessary for the survival in the presence of oxidative stress. Dps is also a virulence factor which activates neutrophils, mast cells and monocytes. HP-NAP binds to neutrophil-glycosphingolipids and to sulfated carbohydrates on mucin. HP-NAP might play a part in the accumulation of neutrophils and monocytes at the site of infection. HP-NAP induces superoxide anion generation, adhesion and chemotaxis of neutrophils, via a pertussis toxin-sensitive pathway involving MAP kinases.

ASCC1 is a subunit of the triggering signal cointegrator 1 (ASC-1) complex which is a transcriptional coactivator. ASC-1 complex takes a vital part in gene transactivation using various transcription factors such as activating protein 1 (AP-1), nuclear factor kappa-B (NF-kB) and serum response factor (SRF). ASCC1 has an N-terminal KH-type RNA-binding motif, essential for AP-1 transactivation by the ASC-1 complex. Alterations in ASCC1 result in Barrett esophagus and esophageal adenocarcinoma.

NME2 takes an important part in the synthesis of nucleoside triphosphates other than ATP. NME2 negatively controls Rho activity by interacting with AKAP13/LBC. NME2 acts as a transcriptional activator of the MYC gene. NME2 binds DNA non-specifically. NME2 is a heterodimeric enzyme functioning as a nucleoside diphosphate kinase. NME1 and NME2 contain 152 amino acids, A and B polypeptide chains of the NM23 enzyme, respectively. NME2 is identical to the beta subunit of human erythrocyte NDP kinase. NDP kinases participate in the synthesis of nucleoside triphosphates, and NM23 is involved in the regulation of signal transduction by complexing with G proteins, causing activation/inactivation of developmental pathways.

ATP synthase subunit O (ATP5O) localizes to the mitochondria and catalyzes ATP synthesis. ATP5O is a component of the F-type ATPase found in the mitochondrial matrix. F-type ATPases are composed of a catalytic core and a membrane proton channel. ATP5O seems to be part of the connector connecting these two components and may be involved in transmission of conformational changes or proton conductance.

EIF1AY is comparable to eukaryotic translation initiation factor 1A (EIF1A). EIF1AY protein is essential for highest rate of protein biosynthesis. EIF1AY increases ribosome dissociation into subunits and is obligatory for the binding of the 43S complex (a 40S subunit, eIF2/GTP/Met-tRNAi and eIF3) to the 5' end of capped RNA.

Eotaxin-2, also called MPIF2 & Ckb6, is a novel CC chemokine produced by activated monocytes and T lymphocytes. Eotaxin-2 selectively chemoattracts cells expressing CCR3 including eosinophils, basophils, Th2 T cells, mast cells, and certain subsets of dendritic cells. Furthermore, Eotaxin-2 inhibits the proliferation of multipotential hematopoietic progenitor cells. The mature protein, which includes C-terminal truncation, contains 78 amino acids (92 amino acids for the mouse homolog, without C-terminal truncation).
CCL24 functions as a chemotactic chemokine for resting t-lymphocytes, and eosinophils. CCL24 has lower chemotactic activity for neutrophils but none for monocytes and activated lymphocytes. CCL24 is a strong suppressor of colony formation by a multipotential hematopoietic progenitor cell line and binds to CCR3.

BLOC1S2 is a member of the BLOC1S2 family. Biogenesis of lysosome-related organelles complex 1 or BLOC-1 is a universally expressed multisubunit protein complex which is essential for regular biogenesis of specialized organelles of the endosomal-lysosomal system, like melanosomes and platelet dense granules. BLOC1S2 takes part in cell proliferation.

FABP1 (Fatty acid binding protein1) encodes the fatty acid binding protein found in liver. FABP1 is composed of ten antiparallel beta strands that form a barrel with a bigger binding pocket than the other FABPs allowing it to accommodate two fatty acid. This protein binds free fatty acids and their coenzyme A derivatives, bilirubin, and some other small molecules in the cytoplasm; it may be involved in intracellular lipid transport and metabolism.