Production of a biologically active recombinant growth hormone from pejerrey (Odontesthes bonariensis)

SCIARA, ANDRÉS A.; SOMOZA, GUSTAVO M.; ARRANZ, SILVIA E.

Rosario, Argentina

Congreso; XLII Reunión anual de la Sociedad Argentina de Investigacion en Bioquímica y de Bilogía Molecular; 2006

Sociedad Argentina de Investigacion en Bioquímica y de Bilogía Molecular

Since economical equation in fisheries is conditioned on fish growing rates, growth hormone based studies became a key factor in aquaculture development. Current pejerrey cultures do not provide adequate growing rates for commercial applications. Oral administration of active growth hormone is a valid tool to promote growth in teleost fish. The aim of this work was to obtain an active recombinant pejerrey growth hormone (pjGHr) by the optimization of the solubilization and refolding of pjGHr produced in a highly efficient prokaryotic system. Hormone cDNA inserted in pET-24 vector was expressed in E.coli BL21 CodonPlus. Cells were induced with 2 g/l lactose obtaining 0.4 g/l pjGHr with a 83 % purity. To achieve an efficient refolding, inclusion bodies were solubilized in 8M Urea, Tris 100mM pH 10.5. The optimal refolding condition was obtained by dilution of the protein solution in ten volumes of Tris 40mM pH 10.5 with Arginine 50 mM used as an intermolecular interaction inhibitor. Finally the dilution was dialyzed 24 hs against Tris 20mM pH 9 followed by 12 hs against sodium bicarbonate 0.05%. Juvenil pejerrey injected with 0.5 ug of pjGHr per gram of body weight exhibited significant increase (P 0.05) of hepatic IGF-I mRNA measured by semi-quantitative RT-PCR. Active pjGHr production is the first step to achieve an improvement of growing rates of this specie.