Comparative study of two proteases for mass spectrometric method for the determination HbA1c / 中华检验医学杂志

ABSTRACT

Objective To explore the difference of two kinds of proteolytic enzymes (GLU-C and Lys-C trypsin),hemoglobin A1c were measured in mass spectrometry.Methods Based on the IFCC recommended hemoglobin A1c reference measurement method by mass spectrometry,the blood samples were preparied (the number of these blood samples201201,201202,201203).Hemoglobin in the samples were enzymed respectively by two kinds of proteolytic enzymes (Glu-C and Lys-C),before the mass spectra which be used solid phase extraction method,under the optimal experimental conditions,hemoglobin A1c in the sample were measured by the liquid chromatography tandem mass spectrometry and screened of variant hemoglobin with sequest software.All results by mass spectrometry are required to use the Sequest software to search RAW file in the human IPI Database,retrieve four common hemoglobin variant published results and compare hemoglobin variant sites,using statistical software SPSS13.0 and Excel 2003 on the results in the correlation analysis,compare between groups by the independent sample t test.Results In the detection of hemoglobin A1c,respectively Glu-C and Lys-C blood which the samples were enzymed,results of hemoglobin A1c by Lys-C were (34.70 ± 2.80),(51.76 ± 1.60),(73.39 ± 1.11) mmol/mol,results of hemoglobin A1c by Glu-C were(33.12 ± 1.48),(54.54 ± 2.50),(75.40 ± 3.60) mmol/mol,the difference between groups was not statistically significant,the results of two methods of drawing curve,all R2 ＞ 0.995.Searching the human database with sequest software,four common hemoglobin variant were not be finded.Conclusions In the detection of hemoglobin A1c by the mass spectrometry,the application of the above two kinds of proteolytic enzyme in the blood samples,that can be more consistent results,test results of two methods have a good correlation.