title: [Comparative study of properties of two extracellular protectors, isolated from Escherichia coli at elevated temperature].
abstract: The regularities of the formation and action, as well as some physicochemical properties, of two extracellular protectants secreted by Escherichia coli cells under the condition of heat shock (a temperature increase from 37 to 46-49 degrees C), were investigated. Both factors, "antilysin" (factor X(I)), either protecting from, or diminishing, cell lysis under the action of 9 microM N-ethylmaleimide (NEM), and "mu-reducer" (factor X(II)), reducing the rate of culture growth after a 60-min incubation and increasing culture viability in the presence of 200 microM NEM, were shown to be low-molecular-weight substances (less than 10 kDa) stable at extreme (pH values pH 1 and pH 11). Factors X(I) and X(II) differed in the dynamics of their accumulation in the culture liquid under unfavorable conditions and in the dependence pattern of their action upon concentration. Unlike factor X(II), factor X(I) was highly unstable during heating and storage. By their characteristics, X(I) should be considered a protectant, or an adaptogen of direct action, and X(II) to an inductor activating the cellular system to enhance cell viability.
authors.affiliation: Institute of Microbiology, Russian Academy of Sciences, Moscow, Russia.
authors.forename: Iu A
authors.initials: IuA
authors.lastname: Nikolaev
mesh_terms: D001426:Bacterial Proteins / Q000302:isolation & purification* / Q000378:metabolism; D004926:Escherichia coli / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism; D005033:Ethylmaleimide / Q000494:pharmacology; D006360:Heat-Shock Proteins / Q000302:isolation & purification* / Q000378:metabolism; D018869:Heat-Shock Response; D006863:Hydrogen-Ion Concentration
chemical_list: D001426:Bacterial Proteins; D006360:Heat-Shock Proteins; D005033:Ethylmaleimide
vernacular_title: Sravnitel'noe izuchenie svoĭstv dvukh vnekletochnykh protektorov, vydeliaemykh Escherichia coli pri povyshennoĭ temperature.