What is Phos-tag?

Phos-tag is a compound that labels compounds having an anionic group. The labeled compounds may be either natural compounds or synthetic compounds. The products that have been developed and commercialized this time are especially effective for compounds with a phosphate group.

Under neutral pH conditions (physiological conditions), Phos-tag binds with an anionic substituent, especially strongly with a phosphomonoester dianion. Phos-tag can take the place of conventional enzyme immunoassay and radioactive isotope methods as an agent for capturing substances with an anionic substituent, especially a phosphomonoester dianion. Unstable phosphorylated compounds, which were difficult to measure up until now due to instability, can also be stabilized.

What is Phos-tag technology?

The phosphorylation and dephosphorylation of proteins are important themes relevant to information transmission in living bodies and are crucial for life functions. The clarification of such phosphorylation processes is a major theme of post-genome research and is targeted in the development of new drugs.

Conventional technologies and their problems are as follows:

Phos-tag technology makes use of the properties of Phos-tag, that is, the properties of binding strongly under neutral pH conditions (physiological conditions) to anionic substituents, especially phosphomonoester dianions, and takes the place of conventional enzyme immunoassay and radioactive isotope methods as a technology for capturing substances with an anionic substituent, especially a phosphomonoester dianion, as well as stabilizing unstable phosphorylated compounds, which were difficult to measure up until now due to instability. Generally with a captured compound, the captured anionic compound dissociates at a pH of 3 to 4.

Applications

The properties of Phos-tag, which enable labeling of most compounds having a phosphate group in the molecule, such as proteins, nucleic acids, and other biochemical substances, can be put to use in the following applications. The phosphate group of a phosphorylated compound can be capped to detect an unknown donor by nuclear magnetic resonance or mass spectrometry measurements of the spin difference or mass difference with respect to a reference sample. Chromatography can be used to detect the change in mass that is caused by Phos-tag binding to the analyzed compound, and electrophoresis can be used due to the electrical change caused by the addition of Phos-tag's charge. Phos-tag can be bounded to a plate, resin, beads, fibers, etc. for capture of a donor and separation of phosphorylated compounds from non-phosphorylated compounds. By selection of the plate, resin, fibers, etc. to which Phos-tag is bound, separation according to the number of phosphate groups is enabled.

The following applications can be considered: