title: [Synthesis, secretion, and proteolytic degradation of diphtheria toxin in Escherichia coli].
abstract: The recombinant plasmids have been constructed encoding the synthesis of a full-sized diphtheria toxin from its own or PR, PL-promoters of bacteriophage lambda in Escherichia coli cells. The high level constitutive synthesis of toxin results in slow cell growth and plasmid elimination. The toxin was mainly detected in the periplasm, partially in the membrane and to a less extent in the cytoplasm and culturing medium. The dimeric form of toxin was found in the cytoplasm. Participation of toxin B-subunit in secreting of the toxin into culturing medium is discussed. Proteolytic degradation of the synthesized toxin in different Escherichia coli strains was demonstrated. The process takes place in cytoplasm and periplasm mainly. The main enzyme participating in the process is a La-protease. The data on proteolysis obtained by immunoprecipitation immunoblotting, affinity chromatography and in mini-cells of Escherichia coli are summarized.
authors.forename: V A
authors.initials: VA
authors.lastname: Shmelev
authors.forename: O N
authors.initials: ON
authors.lastname: Perovskaia
authors.forename: P Kh
authors.initials: PKh
authors.lastname: Kopylov
authors.forename: L Iu
authors.initials: LIu
authors.lastname: Nosova
authors.forename: S G
authors.initials: SG
authors.lastname: Popov
mesh_terms: D001345:Autoradiography; D010582:Bacteriophage lambda / Q000235:genetics; D015153:Blotting, Western; D002846:Chromatography, Affinity; D003470:Culture Media / Q000737:chemistry; D004167:Diphtheria Toxin / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism*; D015870:Gene Expression; D005814:Genes, Viral; D006868:Hydrolysis; D010957:Plasmids; D010960:Plasminogen Activators / Q000378:metabolism; D011233:Precipitin Tests; D011401:Promoter Regions, Genetic; D015183:Restriction Mapping; D013045:Species Specificity; D015010:Yersinia pestis / Q000378:metabolism
chemical_list: D003470:Culture Media; D004167:Diphtheria Toxin; D010960:Plasminogen Activators
vernacular_title: Sintez, sekretsiia i proteoliticheskaia degradatsiia difteriĭnogo toksina v Escherichia coli.