Glycation of N-epsilon-carboxymethyllysine

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

Abstract

The Maillard reaction is traditionally subdivided into three stages that start consecutively and run in parallel. Here, we show that N-epsilon-carboxymethyllysine (CML), a compound formed in the late stage of the reaction, can undergo a second glycation event at its secondary amino group leading to a new class of Amadori rearrangement products. When N-alpha-hippuryl-CML was incubated in the presence of reducing sugars such as glucose, galactose, ribose, xylose, maltose, or lactose in solution for 1 h at 75 degrees C, the compound was degraded by 6-21%, and N-epsilon-carboxymethyl-N-epsilon-deoxyketosyl lysine derivatives were formed. Under the same conditions, lysine was 5-10 times more reactive than CML. N-alpha-hippuryl-N-epsilon-carboxymethyl-N-epsilon-(1-deoxyfructosyl)-L-lysine (hippuryl-CMFL) and N-epsilon-carboxymethyl-N-epsilon-(1-deoxyfructosyl)-L-lysine (CMFL) were synthesized, isolated and characterized by MS/MS and NMR experiments. Depending on the reaction conditions, up to 21% of CMFL can be converted to the furosine analogue N-epsilon-carboxymethyl-N-E-furoylmethyl-L-lysine (CM-Fur) during standard acid protein hydrolysis with hydrochloric acid. Incubation of bovine serum albumin (BSA) with glucose for up to 9 weeks at 37 degrees C revealed the formation of CMFL in the protein as assessed by HPLC-MS/MS in the MRM mode. Under these conditions, ca. 13% of lysine residues had been converted to fructosyllysine, and 0.03% had been converted to CMFL. The detection of glycation products of glycated amino acids (heterogeneous multiple glycation) reveals a novel pathway in the Maillard reaction.

Details

Original languageEnglish
Pages (from-to)825-837
Number of pages13
JournalEuropean Food Research and Technology
Volume248
Issue number3
Publication statusPublished - 1 Mar 2022
Peer-reviewedYes

External IDs

Scopus 85121358724
Mendeley 24b95730-770c-37e2-b481-b2d7a8d31378
unpaywall 10.1007/s00217-021-03931-7
ORCID /0000-0001-8528-6893/work/142256487

Keywords

Keywords

  • Maillard reaction, Glycation, Amadori product, N-E-carboxymethyllysine, Furosine, MAILLARD REACTION-PRODUCTS, CACO-2 CELL MONOLAYERS, END-PRODUCTS, TRANSEPITHELIAL FLUX, ACID-HYDROLYSIS, LYSINE, DEGRADATION, ENDPRODUCTS, MECHANISM, AMADORI, N-ε-carboxymethyllysine