JOAO EZEQUIEL DE OLIVEIRA
5 resultados
Resultados de Busca
Agora exibindo 1 - 5 de 5
Artigo IPEN-doc 22995 N-Glycoprofiling analysis for carbohydrate composition and site-occupancy determination in a poly-glycosylated protein: human thyrotropin of different origins2017 - RIBELA, MARIA T.C.P.; DAMIANI, RENATA; SILVA, FELIPE D.; LIMA, ELIANA R.; OLIVEIRA, JOAO E.; PERONI, CIBELE N.; TORJESEN, PETER A.; SOARES, CARLOS R.; BARTOLINI, PAOLOHuman thyrotropin (hTSH) is a glycoprotein with three potential glycosylation sites: two in the -subunit and one in the -subunit. These sites are not always occupied and occupancy is frequently neglected in glycoprotein characterization, even though it is related to folding, trafficking, initiation of inflammation and host defense, as well as congenital disorders of glycosylation (CDG). For the first time N-glycoprofiling analysis was applied to the site-occupancy determination of two native pituitary hTSH, in comparison with three recombinant preparations of hTSH, a widely used biopharmaceutical. A single methodology provided the: (i) average N-glycan mass; (ii) mass fraction of each monosaccharide and of sulfate; and (iii) percent carbohydrate. The results indicate that the occupancy (65%–87%) and carbohydrate mass (12%–19%) can be up to 34%–57% higher in recombinant hormones. The average glycan mass is 24% lower in pituitary hTSH and contains ~3-fold fewer moles of galactose (p < 0.005) and sialic acid (p < 0.01). One of the two native preparations, which had the smallest glycan mass together with the lowest occupancy and GalNAc, sulfate, Gal and sialic acid contents, also presented the lowest in vivo bioactivity and circulatory half-life. The methodology described, comparing a recombinant biopharmaceutical to its native equivalent, can be applied to any physiologically or clinical relevant glycoprotein.Artigo IPEN-doc 16538 Improved bioprocess with CHO-hTSH cells on higher microcarrier concentration provides higher overall biomass and productivity for rhTSH2011 - VENTINI, DANIELLA C.; DAMIANI, RENATA; SOUSA, ALVARO P.B.; OLIVEIRA, JOAO E. de; PERONI, CIBELE N.; RIBELA, MARIA T.C.P.; BARTOLINI, PAOLO; TONSO, ALDO; SOARES, CARLOS R.J.; PEREIRA, CARLOS A.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 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.