Extracellular production of a functional soy cystatin by Bacillus subtilis.
A recombinant Bacillus subtilis producing soy cystatin was developed by subcloning with a soy cystatin gene cloned in Escherichia coli. An active form of cystatin against the cysteine protease from Pacific whiting fillets contaminated with Myxosporidia parasite was constitutively expressed and secreted extracelluarly into the medium. Two gene fragments of signal peptides from kerA and sacB were introduced and compared for secretion efficiency of cystatin. The secretion level of active cystatin improved with the signal peptide of kerA when compared to that of sacB. Inhibitor activity was reduced rapidly after peak expression of the target protein at 36 h of fermentation. The addition of 1% glucose, a suppressor of protease, into the medium sustained the increase of the cystatin activity during fermentation. This study introduced a potential new method for fermentation production of cystatin.
Kang
Ik Soon
IS
Department of Food Science, North Carolina State University, Raleigh, North Carolina 27695, USA.
Wang
Jeng-Jie
JJ
Shih
Jason C H
JC
Lanier
Tyre C
TC
D001412:Bacillus subtilis / Q000235:genetics*; D003001:Cloning, Molecular; D015891:Cystatins / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics; D005947:Glucose / Q000494:pharmacology; D011994:Recombinant Proteins; D013025:Glycine max / Q000737:chemistry* / Q000235:genetics; D014162:Transfection
D015891:Cystatins; D011994:Recombinant Proteins; D005947:Glucose