Bacterial enzymes that can deglycate glucose- and fructose-modified lysine

Abstract

Deglycating enzymes, i.e. enzymes that reverse the initial stage of the Maillard reaction between glucose and primary amines, are known to occur in mammalian, fungal and other eukaryotic and prokaryotic cells. In this issue of Biochemical Journal, Wiame et al. now report the existence of bacterial enzymes and an operon that control the metabolism and deglycation of glucoselysine 6-phosphate, i.e. the phosphorylated condensation product of fructose and ε-aminolysine. The discovery has broad implications for bacterial metabolism and possibly for the repair of protein damage by fructose.

Reduced fructosamine-3-kinase activity and its mRNA in human distal colorectal carcinoma

“…1a). According to our previous study [16], the mean level of FN3K mRNA was significantly lower in cancer than in the corresponding normal colorectal mucosa, being 0.44 ± 0.08 versus 0.74 ± 0.15 (mean values ± SE), respectively, expressed as number of mRNA FN3K molecules/number of mRNA b-actin molecules (paired t test, P = 0.03; Fig. 1b).…”

“…However, recent evidence indicates that fructosamines can be repaired by Fructosamine-3-Kinase (FN3K), which phosphorilates fructoselysine (FL) residues on glycated proteins, resulting in the production of protein-bound FL-3-phosphate (FL3P) [16]. The physiological occurrence of deglycation has been proven by showing that protein-bound fructosamines are present at high concentrations in tissues and erythrocytes of FN3K-deficient mice respect to the control mice [4].…”

Growth and transcriptional response of Salmonella Typhimurium LT2 to glucose–lysine-based Maillard reaction products generated under low water activity conditions

“…Although with lower incremental decreases in AGEs (37.5% and 12.2%) and melanoidins (15.5% and 22.8%) in glu-lys2 and glu-lys3, concomitant increases of cell growth compared to the respective controls were observed. While this is the first report on potential fructosyllysine (Amadori product) utilization by Salmonella, previous reports indicated the existence and functionality of deglycating enzymes with bacterial or fungal origin (Monnier, 2005). Escherichia coli can also use fructosyllysine to sustain growth and as an energy substrate via a pathway involving the degradation of the product to glucose 6-phosphate and lysine (Wiame, Lamosa, Santos, & van Schaftingen, 2005).…”

Aging: Drugs to Eliminate Methylglyoxal, a Reactive Glucose Metabolite, and Advanced Glycation Endproducts

“…A number of deglycating enzymes have been discovered, especially in microorganisms, which remove the sugar bound to the protein molecule, and possibly provide these bacteria with energy substrates derived from glycated products [196]. These enzymes, known as amadoriases, include fructosylamine oxidases [197,198], fructosamine-3-kinase [149,150], fructoselysine-6-kinase [199], fructoselysine-3-epimerase (FrlC) [200], and glucoselysine-6-www.intechopen.com Pharmacology 694 phosphate deglycase [201].…”