Identification of N epsilon-(carboxyethyl)lysine, one of the methylglyoxal-derived AGE structures, in glucose-modified protein: mechanism for protein modification by reactive aldehydes.
We have developed a separation system for N(epsilon)-(carboxyethyl)lysine (CEL) and N(epsilon)-(carboxymethyl)lysine (CML) by HPLC equipped with a styrene-divinylbenzene copolymer resin coupled with sulfonic group cation-exchange column and examined whether CEL is formed from proteins modified by glucose via the Maillard reaction. CEL was generated by incubating bovine serum albumin (BSA) with glucose, a reaction inhibited by aminoguanidine, but enhanced by phosphate. Although several aldehydes were detected during incubation of N(alpha)-acetyllysine with glucose, incubation of BSA with methylglyoxal alone generated CEL. These results indicate that methylglyoxal is responsible for CEL formation on protein in vitro.
Nagai
Ryoji
R
Department of Biochemistry, Kumamoto University School of Medicine, Honjo 2-2-1, Japan.
Araki
Tomohiro
T
Hayashi
Cristina Miki
CM
Hayase
Fumitaka
F
Horiuchi
Seikoh
S
D000447:Aldehydes / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D005947:Glucose / Q000737:chemistry*; D017127:Glycation End Products, Advanced / Q000737:chemistry*; D008239:Lysine / Q000031:analogs & derivatives* / Q000032:analysis*; D015416:Maillard Reaction; D011765:Pyruvaldehyde / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000737:chemistry*
D000447:Aldehydes; D017127:Glycation End Products, Advanced; D012710:Serum Albumin, Bovine; C054688:N(6)-(1-carboxyethyl)lysine; D011765:Pyruvaldehyde; D005947:Glucose; D008239:Lysine