Enzymes

Biochemical reactions in cells are catalyzed by a diverse set of functional proteins called enzymes and represent the fundamental processes that control all aspects of cell behaviour and physiology. Enzymes can modulate (i.e., increase or decrease) the rates of a biochemical reaction without being altered in the process. In a biochemical reaction, the molecule at the beginning of the process is called a substrate and it is converted into a different molecule called the product.

The activity of an enzyme can be regulated by different factors. Inhibitors are molecules that decrease enzyme activity while activators are molecules that increase activity. There are many classes of enzymes in any given cell and the enzymes are usually under stringent cellular control since defects in these can have deleterious consequences for the cell. The rate and efficiency of a biochemical reaction is determined by the expression level and the activity state of the appropriate enzyme. A given enzyme can exist in both an "active" and "inactive" state as well as "high" and "low" expression levels in the cell. Depending on which stimuli (growth factors, cytokines or hormones) impacts a cell, this dictates which enzyme component will be turned "on" or "off" and what biochemical reaction will occur.

Biochemical reactions are reversible in nature and different enzymes can catalyze the forward and reverse direction of a given reaction. The ability of enzymes to catalyze a biochemical reaction is an ideal characteristic that has been extensively exploited for drug discovery efforts. Majority of the drugs discovered to date inhibit or activate a given enzyme target and this in turn ultimately determines the effect of a given drug.

There are many types of enzymes in a cell and this includes signalling enzymes (such as protein kinases, protein phosphatases, phosphodiesterases, histone deacteylases) that are involved in post translational modification of proteins and cellular metabolites; house-keeping enzymes that are involved on maintenance and survival of a cell; enzymes involved in growth, division and differentiation of a cell. SignalChem currently offers the following enzymes: active protein kinases, active protein phosphatases, active phosphodiesterases (PDE) and active histone deacetylases (HDAC).

Antibodies

Antibodies or immunoglobulins are heavy (~150 kDa) globular plasma proteins that are produced by the white blood cells of the immune system. Antibodies form a protective mechanism for the body and function to identify and bind with high affinity foreign objects or antigens (such as viruses and bacteria). Recognition of an antigen by an antibody tags it for attack by other parts of the immune system.

Antibodies are large y-shaped proteins with a basic structure comprising of two large heavy chains and two small light chains connected by disulfide bonds. Each antibody has a variable region or V region and a constant region or C region and they can have sugar chains added to some of their amino acid residues. There are several different types of antibody heavy chains, and several different kinds of antibodies, which are grouped into different isotypes based on which heavy chain they possess.

In mammals there are five main isotypes of antibodies ( IgA, IgD, IgE, IgG, and IgM) which perform different roles, and help direct the appropriate immune response for each different type of foreign object they encounter. Though the general structure of all antibodies is very similar, a small region called hypervariable region at the tip of the protein is extremely variable, allowing millions of antibodies with slightly different tip structures to recognize an equally large variety of antigens.

Apart from their protective function in the body, antibodies have also been very useful as selective drug candidates, diagnostic agents, imaging tools and carrier vehicles for delivery of other drugs in the body. Furthermore, antibodies have also played an important role in the understanding of cellular architecture and signalling pathways and can be utilized in multiple ways. Antibodies can be used for protein detection by Western blot, immunoprecipitation, immunohistochemistry, immunocytochemistry and ELISA. In addition, antibodies can also be used for protein purification and immobilization.

Within the Antibodies category, SignalChem currently offers Isoform Specific Antibodies, Primary Antibodies, Secondary Antibodies and Tag Antibodies.

Signaling Reagents

Signal transduction, or the relay of information inside cells, is a fundamental process that determines the health of the cell and the body, and as a consequence, is an area of immense scientific pursuit. Signal transduction is a very complex and yet very controlled process that incorporates many diverse signalling pathways, enzymes and proteins which orchestrate the well being of the cell. Both extra- and intra-cellular factors can modulate or regulate the many diverse signalling pathways, enzymes and proteins in both a positive and negative manner.

The molecular understanding of the networking of the different enzymes and proteins within different signalling pathways has attracted a lot of recent attention since it is a well known fact that defects in signalling pathway components is the direct cause of more than 400 human diseases. Therefore, Signaling Reagents which incorporates proteins, peptides and other reagents are useful tools for understanding basic cell function and disease state.

The signalling proteins that play a role in protein:protein interaction, can act as a scaffold for protein complexes, can modulate enzyme activity or can act as secondary messengers are important tools that can be used to decipher the architecture of signalling pathways. The use of signaling reagents thus allows better understanding of cellular processes such as cell growth, division, differentiation, migration, invasion and cell death. The signaling reagents are useful in basic research and understanding of cell function, in validation studies of key signalling pathways, in assay development for drug discovery effort, as substrate for upstream enzyme targets and as agents for modulating enzyme activity.

SignalChem currently offers the following Signaling Reagents: Cellular Proteins, Unactive Kinases, Peptide Substrates and Reagents for enzymatic assays.

Service Offering

SignalChem offers a broad range of research bioreagents and services including custom protein development and compound profiling. One of the main benefits of working with SignalChem is that through its 50 years of combined experience, our scientific team has the expertise to produce recombinant enzymes and proteins in various expression systems to meet your specifications. Our compound profiling group can assist with the development and optimization of compounds by screening against a single enzyme target or a panel of enzyme targets to establish the specificity of the compound. Compounds can be screened against active enzyme targets such as protein kinases, phosphatases, phosphodiesterases and histone deacetylases. There are over 375 targets in our screening panel and we are continuously expanding our offering to better serve your scientific needs.