Cell Signaling

In biology, cell signaling is a network of communications that governs basic and complex cellular processes. Depending upon the nature of the signal, it can be classified as either biochemical or mechanical. Biochemical signals are generated by biochemical molecules such as proteins, lipids, ions or hormones. Detection of these biochemical agents may shed light on the state of that particular type of signaling pathway.

Disruption of signaling networks often leads to diseases such as cancer, immune diseases and metabolic disorders. By understanding signaling pathways, researchers and clinicians may be able to treat disease conditions effectively and efficiently. AAT Bioquest offers a broad range of assays to conduct cost-effective analysis of various enzymes, proteins or small molecules involved cell signaling pathways. Measure activities such as phosphorylation, methylation and acetylation with unparalleled sensitivity and reproducibility.

Adenosine Diphosphate Assays

Adenosine diphosphate (ADP) is an important organic molecule that plays a major role in cell metabolism. It is a product of ATP dephosphorylation, a key reaction in living cells that is essential for energy transfer, and can be recycled back to ATP via rephosphorylation. This interconversion of ADP and ATP occurs primarily in the mitochondria and chloroplasts by ATPases such as phosphatases, phosphorylases and kinases. ADP is stored in dense bodies inside blood platelets. When platelets are activated, ADP is released to interact with a family of purinergic receptors thereby regulating cellular function.

The PhosphoWorks™ Fluorimetric ADP assay offers a sensitive method for monitoring ADP formation. In this enzyme-coupled assay, ADP formation is measured by monitoring kinase activity due to their proportional relationship.

Figure 1. ADP dose response was measured with the PhosphoWorks™ Fluorimetric ADP Assay Kit (Cat NO. 21655) in a solid black 384-well plate using a Gemini fluorescence microplate reader (Molecular Devices). As low as 0.3 µM ADP can be detected with 15, 30 minutes and 1 hour incubation (Z’ factor =0.65).

Table 1. Biochemical assays for measuring ADP activity, formation or depletion.

Figure 2. ATP dose response was measured with the PhosphoWorks™ Luminescence ATP Assay Kit (Cat No. 21610) on a 96-well white plate using a NOVOstar plate reader (BMG Labtech). The kit can detect 3 pmol ATP with 2 hours incubation (Z’ factor = 0.6, blue 30 minutes, red 1 hour, and green 2 hours). The integration time was 1 sec. The half life is more than 1.5 hours.

Table 2. Biochemical assays for measuring ATP activity, formation or depletion.

Figure 3. cAMP dose response was measured with Screen Quest™ Colorimetric ELISA cAMP Assay Kit (Cat#36370) in a clear 96-well plate with a SpectraMax microplate reader. The Absorbance can be read at 405 nm (blue line), 650 nm (red line) or 740 nm (Green line), the data in figure B are from the incubation with Amplite™ Green for 3 hours.

Table 3. Biochemical assays for monitoring the activation of adenylyl cyclase in G-protein coupled receptor systems.