Production and Bioactivity of Common Carp Recombinant Growth Hormone Protein.

Abstract

This study aimed to produce recombinant growth hormone (rGH) protein of common carp (Cyprinus carpio) and evaluate its bioactivity. DNA fragment encoding mature GH protein of common carp (mCcGH) was amplified by PCR method and PCR products were then ligated into pCold I to generate pCold I-mCcGH protein expression vector. Escherichia coli BL21 (DE3) harboring pCold I-mCcGH was cultured in the 2xYT medium at 15°C for 24 hours and protein production was induced by IPTG. The inclusion bodies containing rGH protein from E. coli transformants were isolated by sonication method and analyzed by SDS-PAGE. The result showed that rGH with molecular weight of about 25 kDa was obtained. Common carp juveniles with average body weight of 5,2±0,4 g were intramuscularly injected once a week for 4 weeks with rGH protein solution from 1 μg bacterial cells per gram fish body weight. The result showed that juveniles fish injected with rGH grew 106,56% higher than control. This result indicated that rGH produced in E. coli BL21 (DE3) possessed biological activity and it may be useful to improve growth of aquaculture species.

Teknologi rekayasa DNA dan protein telah merambah dunia perikanan. Rekayasa DNA seperti transgenik bermanfaat untuk menyisipkan gen-gen yang berguna dan menghasilkan ikan budidaya dengan karakter unggul. Contoh penggunaan teknologi transgenik adalah penyisipan gen penyandi hormon pertumbuhan (growth hormone (GH)) yang dapat memacu pertumbuhan ikan menjadi beberapa kali lipat dari ikan normal (Lutz 2001), anti freeze protein (AFP) yang dapat meningkatkan toleransi ikan pada suhu dingin (Beardmore & Porter 2003) dan pigmen warna yang dapat menghasilkan ikan hias yang lebih menarik dengan beraneka ragam warna. Sementara itu, rekayasa protein yang bermanfaat bagi ikan secara massal dilakukan dengan menggunakan bakteri, ragi, maupun sel sebagai media perbanyakannya (Sekine et al. 1985; Mahmoud 1999; Anathy et al. 2001; Li et al. 2003).