JOAO EZEQUIEL DE OLIVEIRA
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Artigo IPEN-doc 24236 Determination of recombinant Interferon-α2 in E. coli periplasmic extracts by reversed-phase high-performance liquid chromatography2018 - DIAS, PAULO V.S.; ARTHUSO, FERNANDA S.; OLIVEIRA, JOAO E.; SUZUKI, MIRIAM F.; SOUSA, JOSE M.; RIBELA, MARIA T.C.P.; BARTOLINI, PAOLO; SOARES, CARLOS R.J.Reversed-phase high-performance liquid chromatography (RP-HPLC) has been used to analyze Interferon α-2 (IFN-α2) as a pure protein or as a pharmaceutical preparation: a method for analyzing periplasmic IFN-α2 directly in osmotic shock extract has, however, never been reported. This work describes an RP-HPLC methodology for the qualitative and quantitative analysis of human IFN-α2a and IFN-α2b directly in bacterial periplasmic extracts or in purified preparations. The analytical method has been set up and validated for accuracy, precision, linearity, sensitivity and specificity. A recovery test indicated an average bias of ∼1%, intra-day and inter-day quantitative determinations presented relative standard deviations always ≤ 5%, while the working sensitivity was of ∼0.3 μg of IFN-α2 (RSD =5%). The method proved to be suitable for detecting and quantifying also glycosylated and oxidized forms and N-methionylated IFN-α2 molecules, it was, however, not able to distinguish between IFN-α2a and IFN-α2b. This rapid methodology allows the application of RP-HPLC as a powerful tool to monitor the production yield and quality of IFN-α2 in osmotic shock fluids, right after, or even during the fermentation process.Artigo IPEN-doc 20113 Reversed-phase performance liquid chromatography as an alternative to animal bioassay for human thyrotropin potency determination2014 - ALMEIDA, B.E.; DAMIANI, R.; OLIVEIRA, J.E.; DALMORA, S.L.; TORJESEN, P.A.; BARTOLINI, P.; RIBELA, M.T.C.P.Artigo IPEN-doc 08961 Determination of Chinese hamster ovary cell-derived recombinant thyrotropin by reversed-phase liquid chromatography2003 - OLIVEIRA, J.E.; MENDONCA, F.; PERONI, C.N.; BARTOLINI, P.; RIBELA, M.T.C.P.Artigo IPEN-doc 14267 Stable expression of a human-like sialylated recombinant thyrotropin in a Chinese hamster ovary cell line expressing α2,6-sialyltransferase2009 - DAMIANI, RENATA; OLIVEIRA, JOAO E.; VORAUER-UHL, KAROLA; PERONI, CIBELE N.; VIANNA, ELIZABETH G.; BARTOLINI, PAOLO; RIBELA, MARIA T.C.P.A CHO cell line, previously genetically modified by the introduction of rat α2,6-sialyltransferase cDNA, generated for the first time a human-like sialylated recombinant hTSH (hlsr-hTSH) more similar to the native hormone, with 61% of α2,3- and 39% of α2,6-linked sialic acid residues. The best clone, when submitted to gene amplification with up to 8 μM methotrexate, presented a secretion level of ∼2 μg hTSH/106 cells/day, useful for product purification and characterization. The relative molecular masses (Mr) of the heterodimer and of the α- and β-subunits of purified hlsr-hTSH, determined by MALDI-TOF mass spectrometry, and the relative hydrophobicities, determined by RP-HPLC, were not remarkably different from those presented by two r-hTSH preparations secreted by normal CHO cells. Some differences were observed, though, in N-glycan composition, with more tri- and much more tetra-sialylated structures in hlsr-hTSH. When analyzed via an in vivo bioassay based on hTSH-induced T4 release in mice, hlsr-hTSH was shown to be equipotent (p > 0.05) with the commercial preparation of r-hTSH (Thyrogen), and 1.6-fold more potent than native hTSH (p < 0.001).Artigo IPEN-doc 14984 Analysis of human luteinizing hormone and human chorionic gonadotropin preparations of different origins by reversed-phase high-performance liquid chromatography2010 - ALMEIDA, B.E.; OLIVEIRA, J.E.; CARVALHO, C.M.; DALMORA, S.L.; BARTOLINI, P.; RIBELA, M.T.C.P.Artigo IPEN-doc 16425 A pilot study on potency determination of human follicle-stimulating hormone: A comparison between reversed-phase high-performance liquid chromatography method and the vivo bioassay2011 - ALMEIDA, B.E.; OLIVEIRA, J.E.; DAMIANI, R.; DALMORA, S.L.; BARTOLINI, P.; RIBELA, M.T.C.P.Artigo IPEN-doc 17740 Qualitative and quantitative reversed-phase high performance liquid chromatographic analysis of glycoprotein hormones in the presence of a large excess of human serum albumin2012 - ALMEIDA, B.E.; OLIVEIRA, J.E.; DAMIANI, R.; DALMORA, S.L.; BARTOLINI, P.; RIBELA, M.T.C.P.