The glycation of fibronectin by glycolaldehyde and methylglyoxal as a model for aging in Bruch’s membrane
- 293 Downloads
The purpose of the study is to identify the sites of modification when fibronectin reacts with glycolaldehyde or methylglyoxal as a model system for aging of Bruch’s membrane. A synthetic peptide consisting of the α5β1 integrin binding region of fibronectin was incubated with glycolaldehyde for 12 h or with methylglyoxal for 1 h at 37 °C. After tryptic digestion, the samples were analyzed with liquid chromatography–mass spectrometry (LC/MS). Tandem MS was used to determine the sites of modification. The adducts, aldoamine and N ε-carboxymethyl-lysine, attached preferably at lysine residues when the fibronectin peptide reacted with glycolaldehyde. When the fibronectin peptide reacted with methylglyoxal, modifications occurred at lysine and arginine residues. At lysine residues, N ε-carboxyethyl-lysine adducts were present. At arginine residues, hydroimidazolone and tetrapyrimidine adducts were present. Several advanced glycation endproducts were generated when fibronectin was glycated via glycolaldehyde and methylglyoxal. These results can help explain the structural changes Bruch’s membrane undergoes during aging.
KeywordsBruch’s membrane Fibronectin Retinal pigment epithelium Glycation Aging
Compliance with ethical standards
Conflict of interests
The authors do not have competing interests and/or commercial relationships.
The work reported here does not invovle human participants or animal subjects.
- Duran-Jimenez B, Dobler D, Moffatt S, Rabbani N, Streuli CH, Thornalley PJ, Tomlinson DR, Gardiner NJ (2009) Advanced glycation end products in extracellular matrix proteins contribute to the failure of sensory nerve regeneration in diabetes. Diabetes 58(12):2893–2903CrossRefPubMedPubMedCentralGoogle Scholar
- Glenn JV, Beattie JR, Barrett L, Frizzell N, Thorpe SR, Boulton ME, McGarvey JJ, Stitt AW (2007) Confocal Raman microscopy can quantify advanced glycation end product (AGE) modifications in Bruch’s membrane leading to accurate, nondestructive prediction of ocular aging. FASEB J 21(13):3542–3552CrossRefPubMedGoogle Scholar
- Lo TW, Westwood ME, McLellan AC, Selwood T, Thornalley PJ (1994) Binding and modification of proteins by methylglyoxal under physiological conditions. A kinetic and mechanistic study with N alpha-acetylarginine, N alpha-acetylcysteine, and N alpha-acetyllysine, and bovine serum albumin. J Biol Chem 269(51):32299–32305PubMedGoogle Scholar