Bacterial synthesis of recombinant alpha-human atrial natriuretic polypeptide.
The high-level synthesis of alpha-human atrial natriuretic polypeptide hormone in Escherichia coli has been achieved based on the idea that the yield of a small, basic and unstable polypeptide, such as the natriuretic polypeptide, would be improved by fusion with an appropriate protective polypeptide to construct a neutral fused polypeptide. We prepared an expression vector, pCLaHtrp3t, coding a neutral polypeptide containing 130 amino acid residues in which the polypeptide hormone was fused to a newly designed protective polypeptide through lysine as an enzymatically cleavable residue. The fused polypeptide was synthesized at the high level of 32% of total cellular proteins and at 4.7 X 10(6) molecules per single cell. It was recovered as cellular insoluble fraction and purified to homogeneity. For the isolation of the peptide hormone from the resultant fused polypeptide, Achromobacter protease I, a lysine-specific endopeptidase was used, because it has sufficient activity even in 8 M urea. The recombinant natriuretic polypeptide was indistinguishable from native alpha-human atrial natriuretic polypeptide as regards amino acid sequence as well as biological activity.
Saito
Y
Y
Central Research Laboratories, Fujisawa Pharmaceutical Co., Ltd., Osaka.
Ishii
Y
Y
Koyama
S
S
Tsuji
K
K
Yamada
H
H
Terai
T
T
Kobayashi
M
M
Ono
T
T
Niwa
M
M
Ueda
I
I
D000595:Amino Acid Sequence; D009320:Atrial Natriuretic Factor / Q000096:biosynthesis* / Q000235:genetics; D001483:Base Sequence; D004262:DNA Restriction Enzymes; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D005796:Genes; D005813:Genes, Synthetic; D005822:Genetic Vectors; D006801:Humans; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000096:biosynthesis*
D011994:Recombinant Proteins; D009320:Atrial Natriuretic Factor; D004262:DNA Restriction Enzymes