RESUMO
Brugada Syndrome (BS) is a polygenic inherited cardiac disease characterized by life-threatening arrhythmias and high incidence of sudden death. In this study, two-dimensional gel electrophoresis (2D-PAGE) coupled to mass spectrometry (LC-MS/MS) was used to investigate specific changes in the plasma proteome of BS patients and family members sharing the same gene mutation (SCN5AQ1118X), with the aim to identify novel disease biomarkers. Our data demonstrate that the levels of several proteins were significantly altered in BS patients compared with controls. In particular, apolipoprotein E, prothrombin, vitronectin, complement-factor H, vitamin-D-binding protein, voltage-dependent anion-selective channel protein 3 and clusterin were considerably increased in plasma sample of BS patients, whereas alpha-1-antitrypsin, fibrinogen and angiotensinogen were considerably decreased; moreover, post-translational modifications of antithrombin-III were detected in all affected individuals. On the light of these results, we hypothesize that these proteins might be considered as potential markers for the identification of disease status in BS.
Assuntos
Biomarcadores/sangue , Síndrome de Brugada/genética , Proteoma/análise , Antitrombina III/metabolismo , Apolipoproteínas E/genética , Síndrome de Brugada/sangue , Eletrocardiografia , Eletroforese em Gel Bidimensional , Feminino , Humanos , Masculino , Canal de Sódio Disparado por Voltagem NAV1.5/genética , Linhagem , Processamento de Proteína Pós-Traducional , Proteômica/métodos , Protrombina/genética , Espectrometria de Massas em Tandem , alfa 1-Antitripsina/genéticaRESUMO
The complete amino-acid sequence of BS-RNAse, a dimeric ribonuclease isolated from bovine seminal plasma, was determined. The reduced and S-carboxymethylated subunit chain of the enzyme was cleaved by trypsin and chymotrypsin. The resulting peptides, purified by cation-exchange chromatography were sequenced by dansyl-Edman, subtractive Edman degradation and carboxypeptidase A and B digestion. Chymotryptic peptides were used for the alignment. Automated Edman degradation of the native protein, through the N-terminal 41 amino-acid residues, completed the sequence information. The subunit chain of BS-RNAse, composed of 124 amino-acid residues, with a molecular mass of 13,610 Da, is highly homologous (81%) to pancreatic ribonuclease A. A good degree of homology (31%) was also found with human angiogenin. No N-linked carbohydrate-attachment sites, such as Asn-X-Ser/Thr, were found in the protein.