title: Temperature-sensitive immunoglobulin A-binding and dimerization of C-terminus-impaired protein Arp4 produced in Escherichia coli.
abstract: 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.
authors.affiliation: Sumitomo Chemical Co., Ltd., Takarazuka Research Center, Hyogo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Nakatani
authors.forename: A
authors.initials: A
authors.lastname: Higuchi
authors.forename: H
authors.initials: H
authors.lastname: Noguchi
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics; D006801:Humans; D007070:Immunoglobulin A / Q000378:metabolism*; D066298:In Vitro Techniques; D008970:Molecular Weight; D011487:Protein Conformation; D011961:Receptors, Fc; D011971:Receptors, Immunologic / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013205:Staphylococcal Protein A / Q000378:metabolism; D013297:Streptococcus pyogenes / Q000235:genetics; D013696:Temperature
chemical_list: C062462:Arp4 protein, Streptococcus pyogenes; D001426:Bacterial Proteins; D002352:Carrier Proteins; C045281:IgA receptor; D007070:Immunoglobulin A; D011961:Receptors, Fc; D011971:Receptors, Immunologic; D011994:Recombinant Proteins; D013205:Staphylococcal Protein A