N6-(1-Carboxy-ethyl)-L-lysine


Synonyms: (2S)-2-amino-6-(1-carboxyethylamino)hexanoic acid.
Method(s): GC-MS/MS (1).

What is measured on the same platform, click here.
Platform B: MMA, tHcy, tCys, Met, Ser, Gly, Cysta, Sarc, His, Trp, Kyn, (KTR), HK, KA, XA, AA, HAA, NA, PA, Figlu, Orn, Asp, Glu, Lys, Ala, Phe, Ile, Leu, Pro, Val, Asn, Gln, Thr, Tyr, aKG, 3HIB, aHB, bHB, AcAc, CML, CEL, 2AAA

What is N6-(1-carboxy-ethyl)-L-lysine?

N(6)-(1-carboxyethyl)-L-lysine (CEL) is methylglyoxal-lysine adduct, and one of the advanced glycation end products (AGEs) that is less well studied than its homologue, CML. AGEs are generated by the Maillard reaction (MR) during thermal treatment of foods or are formed in vivo by nonenzymatic chemical reactions, taking place in tissues or fluid where significant concentration of glucose, fructose, or more reactive dicarbonyls react with proteins. CEL is primarily formed by reaction between methylglyoxal and lysine (the AGE path), which is dependent on hyperglycaemia. Thus, the pathways contributing to CEL formation appear to be more limited compared with CML. Like CML, CEL in tissues and serum/plasma increase with age, and have been assigned a role in the pathogenesis of age-related, chronic diseases, including diabetes, cardiovascular disease, Alzheimer's disease and renal dysfunction (2, 3).

Performance of the assay

Lower limit of detection (LOD): na.
Within-day CV: 5 %; between-day CV: na.

Indication(s)

Assessment of AGEs status.

Specimen, collection and processing

Patient/subject: No special precaution.
Matrix: Serum or EDTA plasma.
Volume: Minimum volume is 50 µL, but 200 µL is optimal and allows reanalysis.
Preparation and stability: Stable.

Transportation; for general instruction on transportation, click here.

Frozen, on dry ice.

Reported values, interpretation

Reported values: 0.05-0.40 µmol/L
Intraclass correlation coefficient (ICC): na.

Literature

1. Midttun, Ø., McCann, A., Aarseth, O., Krokeide, M., Kvalheim, G., Meyer, K., and Ueland, P.M. (2016). Combined measurement of 6 fat-soluble vitamins and 26 water-soluble functional vitamin markers and amino acids in 50 μL of serum or plasma by high-throughput mass spectrometry. Anal Chem 88, 10427-436.
2. Chaudhuri, J., Bains, Y., Guha, S., Kahn, A., Hall, D., Bose, N., Gugliucci, A., and Kapahi, P. (2018). The role of advanced glycation end products in aging and metabolic diseases: Bridging association and causality. Cell Metab 28, 337-352.
3. Brings, S., Fleming, T., Freichel, M., Muckenthaler, M.U., Herzig, S., and Nawroth, P.P. (2017). Dicarbonyls and advanced glycation end-products in the development of diabetic complications and targets for intervention. Int J Mol Sci 18, 984.