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Temperature‐Sensitive Immunoglobulin A‐Binding and Dimerization of C‐Terminus‐Impaired Protein Arp4 Produced in Escherichia coli
Author(s) -
Nakatani Tomoyuki,
Higuchi Atsuko,
Noguchi Hiroshi
Publication year - 1992
Publication title -
microbiology and immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.664
H-Index - 70
eISSN - 1348-0421
pISSN - 0385-5600
DOI - 10.1111/j.1348-0421.1992.tb02096.x
Subject(s) - periplasmic space , protein a/g , escherichia coli , protein g , biology , binding protein , biochemistry , microbiology and biotechnology , recombinant dna , protein a , n terminus , enterobacteriaceae , fusion protein , peptide sequence , antibody , gene , immunology
A gene for protein Arp4, an IgA receptor protein derived from Streptococcus pyogenes AP4, was expressed in Escherichia coli . The product was demonstrated to be accumulated in a periplasmic space as a polypeptide with an apparent molecular weight of 40 kDa with the deleted C‐terminal membrane anchor portion of protein Arp4. This 40‐kDa peptide of the C‐terminus‐impaired recombinant protein Arp4 produced in E. coli , designated ir‐protein Arp4, was purified from a periplasmic fraction of transformants and its IgA‐binding activity was analyzed. The IgA binding of ir‐protein Arp4 was temperature‐sensitive, that is, ir‐protein Arp4 bound IgA at 4 and 25 C, but did not at 37 C. In addition, the dimerization of ir‐protein Arp4 was also temperature‐sensitive in parallel with temperature‐dependent binding activity, suggesting that the dimerization of ir‐protein Arp4 may be required for its active binding to IgA. In contrast, ir‐protein Arp4 immobilized on Sepharose 4B did bind to IgA even at 37 C as well as 4 and 25 C. The immobilized ir‐protein Arp4 might acquire the temperature‐resistant IgA binding activity in part through the formation of a stable dimerized ir‐protein Arp4 on the solid support.