Characterization of three species of Escherichia coli-derived human leukocyte interferon A separated by reverse-phase high-performance liquid chromatography.
A preparation of recombinant human leukocyte interferon A (rIFN-alpha A) obtained from Escherichia coli cells was found by reverse-phase high-performance liquid chromatography (HPLC) to contain three species. The three species, named Mf-1, Mf-2, and Ms in the order of their elution, were separated and characterized to elucidate their structural differences. The amino acid compositions, the amino-terminal amino acid sequences (Cys1-Asp2-Leu3-), and the carboxy-terminal amino acids (Glu) of the three species agreed with those predicted from the cDNA sequence, although the sequence analysis yields of Mf-2 and Ms were extremely low. They were found to have the same disulfide bonds, Cys1-Cys98 and Cys29-Cys138, by amino acid analysis of the tryptic peptides, but the recovery of the peptides linked by a Cys1-Cys98 disulfide bond for Mf-2 and Ms was extremely low. The results demonstrate that although the primary structures of the three species are almost identical, small difference(s) exists among them especially at the amino-terminal portion.
Nakagawa
S
S
Honda
S
S
Sugino
H
H
Kusumoto
S
S
Sasaoki
K
K
Nishi
K
K
Kakinuma
A
A
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D002851:Chromatography, High Pressure Liquid; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics; D006801:Humans; D007370:Interferon Type I / Q000235:genetics / Q000302:isolation & purification*; D010084:Oxidation-Reduction; D010446:Peptide Fragments / Q000302:isolation & purification
D000596:Amino Acids; D007370:Interferon Type I; D010446:Peptide Fragments