In-vivo processing of the initiator methionine from recombinant methionyl human interleukin-6 synthesized in Escherichia coli overproducing aminopeptidase-P.
Human interleukin 6 (hIL-6) overproduced in Escherichia coli HB101 was found to partially retain the initiator methionine (Met) residue (Met-hIL-6). In order to remove the residual N-terminal Met in vivo, an attempt was made to express hIL-6 in aminopeptidase-P (Ap-P)-hyperproducing strains, since the N-terminus Met-Pro- structure of nascent recombinant hIL-6 has been shown to be a favoured substrate of the enzyme in vitro. Using a mutant with duplicated Ap-P genes (pepP) on a chromosome or some recombinant strains overproducing Ap-P, we have succeeded in removing the initiator Met from Met-hIL-6 in vivo. The content of the mature product without the initiator Met in the pepP recombinant strains could be increased to approximately 99% from 85%.
Yasueda
H
H
Central Research Laboratories, Ajinomoto Co., Kanagawa, Japan.
Kikuchi
Y
Y
Kojima
H
H
Nagase
K
K
D000595:Amino Acid Sequence; D000626:Aminopeptidases / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D015850:Interleukin-6 / Q000096:biosynthesis*; D008715:Methionine; D008969:Molecular Sequence Data; D010442:Peptide Chain Initiation, Translational; D011499:Protein Processing, Post-Translational; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis*
D001426:Bacterial Proteins; D015850:Interleukin-6; D011993:Recombinant Fusion Proteins; D008715:Methionine; D000626:Aminopeptidases