An enzymatic method for the measurement of glycated albumin in biological samples.
BACKGROUND
In order to determine glycated albumin more easily and rapidly, we developed a new enzymatic method for glycated albumin in blood samples.


METHODS
The method involves use of albumin-specific proteinase, ketoamine oxidase and serum albumin assay reagent. In the assay, glycated albumin is hydrolyzed to glycated amino acids by proteinase digestion, and ketoamine oxidase oxidizes the glycated amino acids to produce hydrogen peroxide, which is quantitatively measured. Glycated albumin is calculated as the percentage of glycated albumin in total albumin.


RESULTS
The calibration curve for glycated albumin concentration was linear (r(p)=0.999) between 0.0 and 50.0 g/l and that for albumin concentration was linear (r(p)=0.999) between 0.0 and 60.0 g/l. The analytical recoveries of exogenous glycated albumin added to serum were 100-102.5%. The within-run and between-run CVs were 0.45-0.67% and 1.09-1.26%, respectively. This method was free from interference by bilirubin, chyle, glucose, globulins and labile intermediate. Weak interference by hemoglobin and ascorbic acid was observed. Glycated albumin detected by the present method was significantly correlated with glycated albumin detected by high-performance liquid-chromatographic (HPLC) method (serum: r(s)=0.989, plasma: r(p)=0.992).


CONCLUSIONS
This new enzymatic method is simple, rapid, allows multiple determinations and enables quantitative analysis of glycated albumin.
Diagnostics R&D Department, Fine Chemicals and Diagnostics Division, Health Care Company, Asahi Kasei Corporation, 632-1, Mifuku, Ohito-cho, Tagata-gun, Shizuoka-ken, 410-2321, Japan. Kouzuma.tb@om.asahi-kasei.co.jp
Takuji
T
Kouzuma
Tomomi
T
Usami
Masaru
M
Yamakoshi
Mamoru
M
Takahashi
Shigeyuki
S
Imamura
D000596:Amino Acids / Q000032:analysis / Q000737:chemistry; D002138:Calibration; D002851:Chromatography, High Pressure Liquid; D003902:Detergents; D003920:Diabetes Mellitus / Q000097:blood; D010450:Endopeptidases / Q000378:metabolism*; D017127:Glycation End Products, Advanced; D006801:Humans; D006943:Hyperglycemia / Q000097:blood; D010088:Oxidoreductases / Q000378:metabolism; D011485:Protein Binding; D012680:Sensitivity and Specificity; D012709:Serum Albumin / Q000032:analysis*; D013379:Substrate Specificity; D013997:Time Factors; D000093423:Glycated Serum Albumin
D000596:Amino Acids; D003902:Detergents; D017127:Glycation End Products, Advanced; D012709:Serum Albumin; D010088:Oxidoreductases; D010450:Endopeptidases; D000093423:Glycated Serum Albumin