Glicoproteínas séricas ligantes da lectina de dioclea altíssima no estudo de doenças prostáticas

Abstract

Nowadays there are an increase number of studies based on the change of glycoproteomics profiles in several diseases, especially in the search for serum biomarkers for cancer. The direct identification and quantification of serum glycoprotein of low abundance are difficult, because proteins very abundance in the blood can difficult the identification. Thus, fractionation tools are necessary to isolate efficiently changed protein glycoforms on the blood proteome. Given the specific and reversible interaction of lectins to glycoconjugates, the use of immobilized lectins on chromatographic matrix has been frequent in order to fractionate complex mixtures, involving glycoprotein for analysis for mass spectrometry. In this context, the goal of this work was to investigate the use of binding glucose/ mannose lectin from Dioclea altíssima seed (DaL) immobilized on Sepharose chromatography matrix 4B® (DaL-Sepharose), on the fractionation of serum glycoproteins and research of potential biomarkers for prostate cancer (PC). Glycoproteins from the retained fraction obtained by chromatography of blood serum on DaL-Sepharose matrix were identified and quantified by mass spectrometry and it was obtained the protein profile to the three groups: control, benign prostatic hyperplasia and PC. The identification of differentially expressed proteins between the groups showed 132 glycoproteins, in which 29 were only identified on the group with prostate cancer or showed one reason of ln greater than 1.2 when compared to quantification on control group. After an analysis, considering the confiability of the identification, estimated by score, and the evidences on the literature that justified a possible involvement of the protein on prostate cancer, stood out: alpha-1-acid glycoprotein, thrombospondin-5 complement C4 A, haptoglobin, pregnancy zone protein, isoform 3 of alpha 1-antitrypsin, alpha-2 glycoprotein rich in leucine and Zinc finger protein. The analysis of fractionated bood serum by DaL-Sepharose matrix with prior depletion of Human Serum Albumin and IgG allowed the identification of alpha 1-antitrypsin and the IGK protein “only” on the group with CaP and the pregnancy zone protein and protein like alfa-1 mieloma up regulated on CaP when compared to the control group. The identification of these glycoproteins generates new perspectives and suit as indicative for guiding research and validation methods development of these results for clinical uses.