Methionine Assay Kit (Fluorometric)

Methionine (Met) is one of the twenty proteogenic amino acids encoded by the genetic code, and one of nine essential amino acids, meaning it cannot be synthesized in vivo and must be obtained from dietary sources. Met is one of two sulfur-containing amino acids (the other being cysteine) and can serve as a precursor in cysteine biosynthesis. S-adenosylmethionine, another product of Met metabolism, is an important co-factor and methyl donor in a number of biological reactions such as methylation and polyamine synthesis. Met is also an intermediate species in the synthesis of phospholipids such as lecithin, and other small precursor molecules including taurine, an aminosulfonic acid. Oxidation of Met generates methionine sulfoxide, a species whose concentration tends to increase with age and is known to cause protein mis-folding and loss-of-function of numerous enzymes. This version of the amino acid can be restored back to methionine by another enzyme, methionine sulfoxide reductase. Biologically, Met levels can affect important events such as angiogenesis, protein synthesis, and cartilage production.

Suitable for the determination of methionine concentration in serum, plasma, cell cultures and tissue lysates

The Methionine Assay Kit utilizes an enzymatic mechanism by which metabolism of methionine is coupled with the stoichiometric generation of hydrogen peroxide. A probe generates fluorometric signal that can be quantified at Ex/Em: 535/587 nm. The assay shows greater than 10-fold specificity for methionine over cysteine and greater than 40-fold selectivity over other standard and non-standard amino acids. After utilization of a proprietary Sample Clean-Up Mix, the method is suitable for use in blood samples, and can detect concentrations as low as 0.5 μM, or 25 pmole Methionine.

Compatible with high-throughput handling systems.