Identification of N-glycan moiety of tumor marker by lectin microarray

Background and purpose:Most of the tumor markers are glycoproteins. The occurrence of cancer is accompanied by changes in glycosylation of related tumor marker. A simple,rapid and high-throughput manner for analyses of the N-glycan moiety of tumor marker is needed in the cancer glycoproteome study in order to identify the N-glycan moiety of tumor marker. Methods:Gel-slide was used as solid support of lectin microarray. The lectin microarray was fabricated with selected lectins to compare the N-glycan moieties of two similar glycoproteins and further to compare the N-glycan compositions of AFPs from different sources. Results:There was a linear relationship between the ? uorescence intensity and the Cy3 concentration of glycoprotein at the range from 10 to 1000 nmol/L. The optimum loading concentration of lectins in this array is 1 mg/ml. The lectin microarray was sensitive and it could even detect glycoprotein 1 pg. The lectin microarray could indicate the minimal differences of N-glycan compositions between similar glycoproteins and could also indicate the minimal differences of N-glycan compositions between AFPs from different sources. Conclusion:The lectin microarray could be used to identify the N-glycan components of glycoprotein. Gel-slide is a good choice for the fabrication of lectin microarray. The lectin microarray could give a panel of lectin affi nity patterns of individual glycoproteins. It can identify the glyco-label of disease marker,the lectin microarray is important in the early diagnosis of diseases including cancer. The developed lectin affi nity microarray may contribute to the research of glycoproteomics associated with cancer.