title: Oxalic acid-induced modifications of postglycation activity of lysozyme and its glycoforms.
abstract: The role of selected carboxylic acids and their potential to influence the glycation pattern and the enzymatic activity of lysozyme using glucose and ribose were investigated independently of the pH of the reaction medium. The model systems were incubated with and without selected carboxylic acids (maleic, acetic, oxalic, and citraconic) at 50 degrees C for 12 or 24 and 48 h at constant pH of 6.5. The effect of carboxylic acids on the glycation of lysozyme was studied by electrospray ionization mass spectrometry (ESI-MS) and by the measurement of the residual enzyme activity of lysozyme in the glycated samples. Of the carboxylic acids evaluated, oxalic acid showed the highest antiglycation activity. The residual lysozyme activity in both oxalic acid-glucose and oxalic acid-ribose systems was >80% compared with 46 and 36% activity in the controls of glucose and ribose systems, respectively. On the other hand, maleic, acetic, and citraconic acid containing systems with both sugars did not exhibit any enhanced enzyme activity relative to the controls. The results of this study show that oxalic acid was unique among the carboxylic acids evaluated with respect to its ability to interact with sugars and inhibit glycation.
authors.affiliation: Department of Food Science and Agricultural Chemistry, McGill University, 21111 Lakeshore, Ste Anne de Bellevue, Quebec, Canada.
authors.forename: Hong Ying
authors.initials: HY
authors.lastname: Gao
authors.forename: Varoujan A
authors.initials: VA
authors.lastname: Yaylayan
authors.forename: Faustinus
authors.initials: F
authors.lastname: Yeboah
mesh_terms: D002264:Carboxylic Acids / Q000494:pharmacology; D005947:Glucose / Q000737:chemistry / Q000378:metabolism; D006031:Glycosylation / Q000187:drug effects; D009113:Muramidase / Q000737:chemistry / Q000378:metabolism*; D019815:Oxalic Acid / Q000737:chemistry / Q000494:pharmacology*; D012266:Ribose / Q000737:chemistry / Q000378:metabolism; D021241:Spectrometry, Mass, Electrospray Ionization; D013329:Structure-Activity Relationship
chemical_list: D002264:Carboxylic Acids; D012266:Ribose; D019815:Oxalic Acid; D009113:Muramidase; D005947:Glucose