Homocysteine (HCY)



Homocysteine Kit (Enzymatic Assay Method)


In vitro test for the quantitative determination of HCY concentration in serum or plasma on photometric systems.Homocysteine (Hcy) is a thiol-containing amino acid produced by the intracellular demethylation of methionine. Total homocysteine (tHcy) represents the sum of all forms of Hcy including forms of oxidized, protein bound and free. Elevated level of tHcy has emerged as an important risk factor in the assessment of cardiovascular disease. Excess Hcy in the blood stream may cause injures to arterial vessels due to its irritant nature, and result in inflammation and plaque formation, which may eventually cause blockage of blood flow to the heart.


Homocysteine (HCY) Kit (Enzymatic Assay Method) is based on the method of S-adenosylhomocysteine (SAH) hydrolase by the small molecule capture technology (SMT). Oxidized HCY is transferred to free HCY by TCEP, which then reacts with a co-substrate, S-adenosylmethionine (SAM), catalyzed by a HCY S-methyltransferase (HMTase) to form methionine and S-adenosylhomocysteine (SAH). Then, SAH is hydrolyzed into adenosine (Ado) and HCY by SAH hydrolase (SAHase). The formed HCY that is originated from the co-substrate SAM is cycled into the HCY conversion reaction by HCY S-methyltransferase. This forms a co-substrate conversion product based enzyme cycling reaction system with significant amplification of detection signals. The formed Ado is immediately hydrolyzed into inosine and ammonia. The enzyme glutamate dehydrogenase (GLDH) catalyzes the reaction of ammonia with 2-oxoglutarate and NADH to form NAD+. The concentration of Hcy in the sample is directly proportional to the amount of NADH converted to NAD+.