Effect of Codon Optimisation on the Production of Recombinant Fish Growth Hormone in Pichia pastoris

Figure 3

SDS-PAGE analysis of oFGH under denaturing and nondenaturing conditions. Recombinant P. pastoris was grown in BGMY media for 48 hrs and then transferred to induction media (BMMY) with continuous induction with 1% absolute methanol for every 12 hrs. The supernatant samples were collected at 12 (L1), 24 (L2), 36 (L3), 48 (L4), 60 (L5), and 72 hrs (L6). The high molecular weight of oFGH multimers (approximately 70 kDa) was observed when the samples were applied for SDS-PAGE without denaturing conditions (heating and reducing by beta-mercaptoethanol (L1–L6)). However, after applying the denaturing conditions only monomer molecules of oFGH were observed at 22 kDa (L7), whilst reducing the samples with beta-mercaptoethanol without heating led to detection of both oFGH monomer (22 kDa) and multimers (70 kDa) (L8).