The development of an integrated platform to identify breast cancer glycoproteome changes in human serum

Protein glycosylation represents one of the major post-translational modifications and can have significant effects on protein function. Moreover, changes in the carbohydrate structure are increasingly being recognized as an important modification associated with cancer etiology. In this report, we describe the development of a proteomics approach to identify breast cancer related changes in either concentration and/or the carbohydrate structures of glycoprotein(s) present in blood samples. Diseased and healthy serum samples were processed by an optimized sample preparation protocol using multiple lectin affinity chromatography (M-LAC) that partitions serum proteins based on glycan characteristics. Subsequently, three separate procedures, 1D SDS-PAGE, isoelectric focusing and an antibody microarray, were applied to identify potential candidate markers for future study. The combination of these three platforms is illustrated in this report with the analysis of control and cancer glycoproteomic fractions. Firstly, a molecular weight based separation of glycoproteins by 1D SDS-PAGE was performed, followed by protein, glycoprotein staining, lectin blotting and LC–MS analysis. To refine or confirm the list of interesting glycoproteins, isoelectric focusing (targeting sialic acid changes) and an antibody microarray (used to detect neutral glycan shifts) were selected as the orthogonal methods. As a result, several glycoproteins including alpha-1B-glycoprotein, complement C3, alpha-1-antitrypsin and transferrin were identified as potential candidates for further study.     

Surfaces tendues dans \mbox{{\bf E}^{3}}: des théorèmes de structure

Sans résumé

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Re?u le 13 February 1997     

Sur La H-Rigidite Des Surfaces Completes De R3

Le théorème fondamental de la théorie localedes surfaces affirme que toute immersion C³ d'une surface dansR³ est déterminée, à congruence près,par sa première et deuxième forme fondamentale.Nous montrerons dans cette note qu'une surface complèteC⁵ de R³ avec |dH| 0 est en fait essentiellement détermineé,à congruence près, par la première formefondamentale et la trace de la seconde, i.e. par la métriqueet la fonction courbure moyenne H. 1991 Mathematics SubjectClassification 53A05, 53A10.