title: Method for monitoring of the protein amino group changes during carbonylation.
abstract: OBJECTIVE
  Carbonylation of the protein amino, guanidino and thiol groups is one of the important causes of vascular complications in diabetes. We developed a simple spectrophotometric method for monitoring of the changes in the protein amino group contents during carbonylation.
  
  
  METHODS
  The method is based on the reaction of amino group with p-benzoquinone in the slightly alkaline media. It was applied during carbonylation in vitro with methylglyoxal and in vivo in 13 patients with type 2 diabetes and 20 healthy persons.
  
  
  RESULTS
  The method is simple, fast, precise (RSD in the range of 1.2-1.8%) and accurate (recovery about 100%). The content of amino groups in human serum albumin isolated from diabetics was significantly lower (p<0.01) in comparison with a control group.
  
  
  CONCLUSIONS
  The method developed is suitable for quantification of protein amino groups during in vitro carbonylation as well as for clinical practice.
authors.affiliation: Faculty of Chemistry, Department of Biochemistry, University of Belgrade, Studentski trg 12-16, Belgrade, Serbia.
authors.forename: Jelena M
authors.initials: JM
authors.lastname: Aćimović
authors.forename: Vesna B
authors.initials: VB
authors.lastname: Jovanović
authors.forename: Milica R
authors.initials: MR
authors.lastname: Veselinović
authors.forename: Vesna Dimitrijević
authors.initials: VD
authors.lastname: Srećković
authors.forename: Ljuba M
authors.initials: LM
authors.lastname: Mandić
mesh_terms: D016227:Benzoquinones / Q000737:chemistry; D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D050050:Protein Carbonylation; D011506:Proteins / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D011765:Pyruvaldehyde / Q000737:chemistry / Q000378:metabolism; D012709:Serum Albumin / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism*; D013053:Spectrophotometry
chemical_list: D016227:Benzoquinones; D011506:Proteins; D012709:Serum Albumin; C004532:quinone; D011765:Pyruvaldehyde