Search results

Members of the Rho (or ARH) protein family and other Ras-related small GTP-binding proteins are involved in various cellular procedures, such as cell cytoskeletal organization, secretion, proliferation, and signaling. The GTPBPs are active only in the GTP-bound state. At least 3 types of proteins firmly regulate cycling between the GTP-bound and GDP-bound states: GDP-dissociation inhibitors (GDIs), GTPase-activating proteins (GAPs) and guanine nucleotide-releasing factors (GRFs). ARHGDIB and the other GDIs lower the level of GDP dissociation from Ras-like GTPases.

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.

HSP27 or Estrogen-Regulated 24K proteinis a part of the mammalian small heat shock protein family. The protein is expressed constitutively in many tissues and its expression is increased to high levels after different types of stress including high temperatures, toxic metals, drugs and oxidants. Furthermore, Hsp27 is phosphorylated in vivo on three phosphorylation sites (Ser15, Ser78 and Ser82) by protein kinases including MAPKAP kinase 2 and the stress-activated protein kinase SAPK2 (p38).

SARS Coronavirus is an enveloped virus containing three outer structural proteins, namely the membrane (M), envelope (E), and spike (S) proteins. Spike (S)-glycoprotein of the virus interacts with a cellular receptor and mediates membrane fusion to allow viral entry into susceptible target cells. Accordingly, S-protein plays an important role in virus infection cycle and is the primary target of neutralizing antibodies.

S100A9 is part of the S100 family of proteins containing 2 EF-hand calcium-binding motifs. S100A9 protein is localized in the cytoplasm and/or nucleus of a wide range of cells, and participates in the regulation of several cellular processes such as cell cycle progression and differentiation. S100 genes include no less than 13 proteins which are localized as a cluster on chromosome 1q21. S100A9 is involved in the inhibition of casein kinase and altered expression of this protein is associated with the disease cystic fibrosis.

Severe acute respiratory syndrome (SARS) has a new causative agent identified as Coronavirus. SARS Associated Coronavirus Spike is one of the main surface antigens of Coronavirus, making it one of the main candidates for vaccines. Diseases caused by Coronaviruses are usually controlled by CD8 T cells.

SHMT1 is a member of the SHMT family. SHMT1 is the cellular form of serine hydroxymethyltransferase, a pyridoxal phosphate-containing enzyme which catalyzes the reversible conversion of serine and tetrahydrofolate to glycine and 5 10-methylene tetrahydrofolate. In addition, SHMT1 specifically provides one-carbon units for thymidylate biosynthesis, reduces methylenetetrahydrofolate pools for S-adenosylmethionine (SAM) synthesis by synthesizing serine, sequesters 5-methyltetrahydrofolate and inhibits SAM synthesis.

MAT2A is an important enzyme in cellular metabolism and catalyzes the formation of S-adenosylmethionine (SAMe) from L-methionine and ATP. MAT2A is expressed in extrahepatic tissues. In liver, MAT2A expression associates with growth, dedifferentiation, and cancer. NF-kappa B and AP-1 are necessary for basal MAT2A expression in HepG2 cells and mediate the increase in MAT2A expression in response to TNF-alpha. Up-regulation of MAT2A provides growth improvement and s-adenosylmethionine and methylthioadenosine thus can block mitogenic signaling in colon cancer cells. Lower expression of both MAT2A and MAT2beta and interfere with leptin signaling in liver cancer cells.

Plasmodium falciparum heat shock proteins (PfHSPs) contribute to immunopathological alterations in infected hosts PfHSP70s may have a significant function during parasite adaptation in its environments. They have also been a focus of considerable attention due to their immunodominant antigenic nature and their properties as mediators of protective immunity.

Mesoderm development candidate 1 (MESDC1) is a member of the MESD family. MESDC1 is a 362 amino acid protein encoded by a gene which maps to human chromosome 15q25.1. MESDC1 serves as a chaperone for low-density lipoprotein receptor (LDLR) proteins in the ER, and specifically associates with Wnt signaling pathway coreceptors LRP5 and LPR6. MESDC1 is needed for proper LRP5/6 folding and maturation to the cell surface, which has a key role in Wnt signaling.

Spermidine/Spermine N1-Acetyltransferase 2, also known as SAT2 catalyzes the acetylation of polyamines (Acetyl-CoA + an alkane-alpha,omega-diamine = CoA + an N-acetyldiamine).

SBDS is part of an extremely preserved protein family which exists from archaea to vertebrates and plants. SBDS protein functions in RNA metabolism and has a role in the biogenesis of the 60S ribosomal subunit and translational activation of ribosomes. Shwachman-Diamond syndrome is a rare autosomal recessive disorder produced by mutations in the SBDS gene.

Sarcoglycan Delta (SGCD) is one of the four known components of the sarcoglycan complex, which is a subcomplex of the dystrophin-glycoprotein complex (DGC) and is expressed mainly in skeletal and cardiac muscle. DGC forms a link between the F-actin cytoskeleton and the extracellular matrix. SGCD protein’s mutations have been associated with autosomal recessive limb-girdle muscular dystrophy and dilated cardiomyopathy. SGCD gene expression is regulated by MITF In melanocytic cells.

Bromodomain Containing 3 (BRD3) was classified based on its homology to the gene encoding the RING3 protein, which is a serine/threonine kinase. The BRD3 protein localizes to 9q34, a region which contains a number of major histocompatibility complex (MHC) genes. The function of the BRD3 protein is unknown.

Thrombospondin-1 (TSP1) is a member of the Thrombospondin family and is encoded by the gene THBS1 which is a subunit of a disulfide-linked homotrimeric protein. Thrombospondin-1 is an adhesive glycoprotein that mediates cell-to-cell and cell-to-matrix interactions. Thrombospondin-1 can bind to fibrinogen, fibronectin, laminin, type V collagen and integrins alpha-V/beta-1. TSP1 has been shown to play roles in platelet aggregation, angiogenesis, and tumorigenesis. TSP1 has been shown to be a natural inhibitor of neovascularization and tumorigenesis in healthy tissue. TSP1 interacts with no less than 12 cell adhesion receptors, including CD36, av integrins, b1 integrins, syndecan, and integrin-associated protein (IAP or CD47). It also interacts with various proteases involved in angiogenesis, including plasminogen, matrix metalloproteinase, thrombin, cathepsin, and elastase. Positive and negative modulation of endothelial cell adhesion, motility, and growth are attributed to TSP1. Recently, thrombospondin-1 was found to bind to the reelin receptors, ApoER2 and VLDLR, in so doing affecting neuronal migration in the rostral migratory stream.

Carcinoembryonic Antigen-Related Cell Adhesion Molecule 21 (CEACAM21) belongs to the family of carcinoembryonic antigen-related cell adhesion molecules (CEACAMs), which are used by a number of bacterial pathogens to bind and invade host cells. The transmembrane protein guides phagocytosis of several bacterial species which is dependent on the small GTPase Rac. CEACAM21 is assumed to have a central role in controlling human-specific pathogens by the innate immune system.

RAD51D is a member of the RAD51 protein family whose members are extremely similar to bacterial RecA and Saccharomyces cerevisiae Rad51. RAD51 protein family members take part in the homologous recombination and repair of DNA. RAD51D forms a complex with several other members of the RAD51 family which catalyzes homologous pairing between single- and double-stranded DNA, and participates in the early stage of recombinational repair of DNA.

Mediator complex subunit 4 (MED4) is a component of the Mediator complex, a coactivator involved in the regulated transcription of nearly all RNA polymerase II-dependent genes. MED4 is a component of the vitamin D receptor-interacting protein (DRIP) complex which functions as a nuclear receptor coactivator. The DRIP complex is able to activate nuclear receptors in a ligand-dependent manner. MED4 functions as a link to convey information from gene-specific regulatory proteins to the basal RNA polymerase II transcription apparatus. MED4 is recruited to promoters by direct interactions with regulatory proteins and serves as a scaffold for the assembly of a functional preinitiation complex with RNA polymerase II and the general transcription factors.

RASD Family Member 2 (RASD2) which binds to GTP and owns a GTPase activity is a part of the Ras super family of small GTPases. RASD2 regulates signaling pathways involving G-proteins-coupled receptor and heterotrimeric proteins. RASD2 encodes a Ras-related protein that enriched in striatum.

MALD1 is a ribonuclease and a heat-sensitive allergen which is a member of the pathogenesis-related protein class. MALD1 shares homologous IgE epitopes with major birch pollen allergen Bet v 1 and Cor a 1 from hazelnut pollen.

Protein A is a cell wall component produced by several strains of Staphylococcus aureus. The recombinant Protein A is genetically engineered protein and holds 5 IgG-binding regions of protein A. Recombinant Protein A functions basically the same as native Protein A and is perfect for purification of polyclonal or monoclonal IgG antibodies. Protein A binds to human IgG1, IgG2 and IgG4, mouse IgG2a, IgG2b and IgG3 and rat IgG2c. Protein A also binds to total IgG from rabbit, pig, dog, cat, and guinea pig.