A sensitive method for the measurement of glycosylated plasma proteins using affinity chromatography.
We describe a simple, sensitive affinity technique for the routine measurement of glycosylated plasma proteins in clinical laboratories. The commercially available phenylboronic acid gel used for the chromatography has recently been marketed as a kit for this purpose (Glycogel Test Kit, Pierce Chemical Co). The manufacturers of this kit recommend loading 200 microliters neat plasma to each 1 ml gel column. This high loading is to enable the direct measurement of protein in the bound and unbound fractions at 280 nm. This loading is consistent with 10-15 mg protein being added per ml gel. Our results show that protein levels greater than 2 mg per ml gel overload the column. Therefore we used a modification of the more sensitive Bradford procedure to measure protein. The method discriminates between normals (6.29 +/- 1.87%) and diabetic patients (12.62 +/- 3.36%) and has good precision (CV 4-6%). The results obtained correlate with the colorimetric method using thiobarbituric acid (r = 0.70) and with glycosylated haemoglobin (r = 0.82).
D001798:Blood Proteins / Q000032:analysis*; D002846:Chromatography, Affinity / Q000379:methods; D003124:Colorimetry; D003920:Diabetes Mellitus / Q000097:blood; D006023:Glycoproteins; D006801:Humans; D012016:Reference Values; D000093422:Glycated Serum Proteins
D001798:Blood Proteins; D006023:Glycoproteins; D000093422:Glycated Serum Proteins