title: Halophilic beta-lactamase as a new solubility- and folding-enhancing tag protein: production of native human interleukin 1alpha and human neutrophil alpha-defensin.
abstract: The amino acid composition of halophilic enzymes is characterized by an abundant content of acidic amino acid, which confers to the halophilic enzymes extensive negative charges at neutral pH and high aqueous solubility. This negative charge prevents protein aggregation when denatured and thereby leads to highly efficient protein refolding. Beta-lactamase from periplasmic space of moderate halophile (BLA), a typical halophilic enzyme, can be readily expressed as a native, active form in Escherichia coli cytoplasm. Similar to other halophilic enzymes, BLA is soluble upon denaturation by heat or urea treatments and, hence, can be efficiently refolded. Such high solubility and refolding efficiency make BLA a potential fusion partner for expression of aggregation-prone heterologous proteins to be expressed in E. coli. Here, we succeeded in the soluble expression of several "difficult-to-express" proteins as a BLA fusion protein and verified biological activities of human interleukin 1alpha and human neutrophil alpha-defensin, HNP-1.
authors.affiliation: Applied and Molecular Microbiology, Faculty of Agriculture, Kagoshima University, 1-21-24 Korimoto, Kagoshima, 890-0065, Japan.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Tokunaga
authors.forename: Shoko
authors.initials: S
authors.lastname: Saito
authors.forename: Kazuki
authors.initials: K
authors.lastname: Sakai
authors.forename: Rui
authors.initials: R
authors.lastname: Yamaguchi
authors.forename: Iwao
authors.initials: I
authors.lastname: Katsuyama
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Arakawa
authors.forename: Kikuo
authors.initials: K
authors.lastname: Onozaki
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Arakawa
authors.forename: Masao
authors.initials: M
authors.lastname: Tokunaga
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D006801:Humans; D053582:Interleukin-1alpha / Q000235:genetics / Q000378:metabolism*; D017510:Protein Folding; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012995:Solubility; D023084:alpha-Defensins / Q000235:genetics / Q000378:metabolism*; D001618:beta-Lactamases / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D053582:Interleukin-1alpha; D011993:Recombinant Fusion Proteins; D023084:alpha-Defensins; C406413:human neutrophil peptide 1; D001618:beta-Lactamases