Figure 4.

SDS-PAGE gel showing expression of recombinant human proinsulin in Pichia pastoris. Standard insulin (lane 10) and expressed human proinsulin at various time intervals (lanes 1–9), in Pichia pastoris, were run in 15% SDS-PAGE. About 10 μL of transformed P. pastoris culture supernatants was loaded into lanes 1–9. As the image revealed, the expressed proinsulin had higher molecular weight (~8 KDa) in comparison with the standard one (lane 10), as it contains the C-peptide. The ~8 KDa band intensity seems increasing with the time intervals 24 h to 96 h as shown from lanes 9 to 1.