Description
Key facts
Detection method:Fluorescent,
Sample types:Plasma, Serum,
Assay type:Quantitative,
Sensitivity:= 5 µM,
Assay Platform:Microplate reader
Product details:
Homocysteine Assay Kit (Fluorometric) (ab228559) allows for quantification of total homocysteine in biological fluids such as plasma and serum. The assay is based on the reduction of homocysteine disulfides to free homocysteine, which is cleaved by a homocysteine-selective enzyme, generating an intermediate product. The intermediate reacts with a probe solution to form a stable fluorophore that emits in the far-red spectrum (Ex/Em = 658/708 nm). The assay is not affected by physiological concentrations of other biological thiols (such as cysteine, methionine and glutathione), is high-throughput adaptable and can detect as low as 5 uM homocysteine.
Other Notes
This product was previously called K531 Homocysteine Assay Kit (Fluorometric). Biovision was acquired by Abcam in 2021.
Homocysteine is a non-proteogenic amino acid synthesized intracellularly by removal of the N-methyl group from the essential amino acid methionine. Homocysteine is exported from cells into the blood, where it exists mainly as an oxidized disulfide species, either as a dimer or bound to cysteine residues of serum proteins. The reduced form of homocysteine ('free' homocysteine) can be metabolized into cysteine via the transsulfuration pathway; however, it can also undergo intramolecular cyclization, forming the highly reactive pro-oxidant homocysteine thiolactone. Subsequent N-homocysteinylation of protein lysine residues by the reactive thiolactone disrupts protein conformation, leading to formation of cytotoxic protein aggregates. Homocysteinylated proteins may also act as autoantigens, triggering arterial inflammation and atherosclerosis. Elevated plasma homocysteine concentration is a clinical biomarker for increased risk of cardiovascular disease, ischemic stroke and myocardial infarction. Severely elevated homocysteine levels (hyperhomocysteinemia) are correlated with a 4-fold increase in mortality due to heart attack and a 16-fold increase in the likelihood of recurrent stroke.
The Safety Datasheet for this product has been updated for certain countries. Please check the current version in the Support and downloads section.
REACH authorisation
Abcam has not and does not intend to apply for the REACH Authorisation of customers' uses of products that contain European Authorisation list (Annex XIV) substances.
It is the responsibility of our customers to check the necessity of application of REACH Authorisation, and any other relevant authorisations, for their intended uses.
Properties and Storage Information:
Shipped at conditions-Blue Ice, Appropriate short-term storage conditions--20°C, Appropriate long-term storage conditions--20°C, Storage information--20°C
Supplementary Information:
This supplementary information is collated from multiple sources and compiled automatically.
Homocysteine is a sulfur-containing amino acid existing mainly in blood plasma and tissues. It is not incorporated directly into proteins but it is converted into other amino acids. Homocysteine originates from methionine an essential amino acid consumed through diet. Homocysteine mass is approximately 135.18 g/mol. It is expressed in the liver kidney and vascular endothelium. Alternative names for homocysteine include Hc and Hcy. The homocysteine test kit is used for quantitative detection of this amino acid in biological samples.
Biological function summary
Homocysteine participates in critical cell processes. It acts within the one-carbon metabolism pathway where it contributes to methylation and sulfur transfer. Homocysteine exists in various forms including free and protein-bound states and it is a precursor for the synthesis of other important molecules like cysteine and taurine. Homocysteine is not part of a large protein complex but interacts with enzymes such as cystathionine β-synthase and methionine synthase.
Pathways
Homocysteine plays a significant role in methylation and transsulfuration pathways. In the methylation pathway homocysteine influences the conversion of methionine to S-adenosylmethionine (SAM) a universal methyl donor involved in DNA methylation. In the transsulfuration pathway homocysteine transforms to cysteine through lyase activity involving the enzyme cystathionine β-synthase. This process is interconnected with proteins like folate and vitamin B12 essential for homocysteine metabolism.
Elevated homocysteine levels correlate with cardiovascular diseases and neurodegenerative disorders. High homocysteine can promote oxidative stress and endothelial dysfunction leading to atherosclerosis. In neurodegenerative diseases like Alzheimer's homocysteine can induce inflammation and neuronal injury. Proteins such as methylenetetrahydrofolate reductase and cystathionine β-synthase are key in these contexts as mutations or dysfunctions in these enzymes can exacerbate homocysteine-related pathologies.
