ALMEIDA, BEATRIZ E.CARVALHO, CRISTIANE M.DAMIANI, RENATAOLIVEIRA, JOAO E.BARTOLINI, PAOLORIBELA, MARIA T.C.P.2014-11-192014-11-192015-04-012014-11-192014-11-192015-04-01ALMEIDA, BEATRIZ E.; CARVALHO, CRISTIANE M.; DAMIANI, RENATA; OLIVEIRA, JOAO E.; BARTOLINI, PAOLO; RIBELA, MARIA T.C.P. Indentity and integraty of 'alfa' and 'beta' - subunit of human thyrotropin prepared by prolonged acetic acid treatment. In: ANNUAL MEETING OF THE BRAZILIAN BIOCHEMISTRY AND MOLECULAR BIOLOGY SOCIETY, 38., May 16-19, 2009, Aguas de Lindoia, SP. <b>Abstract...</b> Disponível em: http://repositorio.ipen.br/handle/123456789/19346.http://repositorio.ipen.br/handle/123456789/19346Alpha- and beta- subunits, prepared by efficiently dissociating, during 16 hours, a recombinant thyrotropin (hTSH) preparation with 0.4 M acetic acid and isolating them by RP-HPLC, were analysed for what concerns their identity and integrity. Identity was evaluated by MALDI-TOF mass spectrometry (MALDI-TOF MS). A relative molecular mass of 14021 and of 15851 was obtained for a-hTSH and (3-hTSH respectively. These values agree with those obtained by analyzing the preparation before dissociation, a difference of -1.8% for a and +1.3% for (3 being observed. Integrity of the subunits was evaluated by their capacity of self reassembling and of restoring the in vivo bioactivity of the hormone. When a-hTSH and I3-hTSH subunits were incubated together in 0.2 M sodium phosphate buffer, pH 7.0, at 25°C and under gentle shaking, a complete reassociation occurred after 4 days, forming an heterodimer. In an in vivo mouse bioassay, the T4 levels of the animals treated with the reassociated hormone were non-significantly different (p> 0.05) from those obtained when the original preparation was administered (2.71± 0.63 pg/dL versus 2.84± 0.23 pg/dL, n=6, respectively). In conclusion, subunits prepared by prolonged acetic acid treatment maintain their original molecular mass and can perfectly restore the biological activity of the reassociated heterodimers.openAccessacetic acidbiochemistryin vivomass spectroscopymicestructural chemical analysistrhtshResumo de eventos científicos