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In vivo processing of N‐terminal methionine in E. coli
Author(s) -
Dalbøge Henrik,
Bayne Stephen,
Pedersen John
Publication year - 1990
Publication title -
febs letters
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(90)90001-b
Subject(s) - humanities , philosophy
The processing of amino-terminal methionine from cytosolic proteins in E. coli has been investigated in vivo, using amino-terminal-extended human growth hormone (hGH) as a model system. Twenty different hGH-genes with the sequence Met-Xxx-Glu-Glu-hGH where Xxx denotes each of the 20 different amino acids, were constructed and expressed in E. coli. Following purification of the products, the N-terminal amino acid sequences (10 cycles) were determined. The results demonstrate that the removal of methionine is dependent on the amino acid adjacent to methionine, and that the processing is strongly correlated to the radius of gyration of this amino acid. In addition, measurement of the hGH expression level from the 20 clones demonstrated that the small difference in the amino acid extension leads to a change in the specific hGH expression rate.