The effect of extracellular recombinant human heat shock protein 70 (Hsp70) on protein pattern observed after endotoxin-induced macrophage activation

The protein pattern of mouse macrophage strain (J774) has been investigated using 2D electrophoresis after combined action of bacterial endotoxins (LPS), heat shock treatment (HS) and administration of recombinant human Hsp70. The investigation demonstrated significant protective effect of HS and recombinant Hsp70 treatment applied before LPS introduction. This effect is apparently realized by means of several signal transduction systems. In the course of the investigation, we have identified eight proteins, which exhibited pronounced changes in their synthesis due to combined treatment. The data accumulated may shed light on molecular mechanisms underlying protective antiseptic action of HS and/or recombinant Hsp70 applied before LPS administration.     

Effect of extracellular recombinant human heat shock protein 70 (HSP70) on protein pattern observed after endotoxin-induced macrophage activation

The protein pattern of murine macrophages cell line J774 has been investigated using 2D electrophoresis after combined action of bacterial endotoxins (LPS), heat shock treatment (HS), and administration of recombinant human Hsp70. The investigation demonstrated significant protective effect of HS and recombinant Hsp70 treatment applied before LPS introduction. This effect is apparently realized by means of several signal transduction systems. In the course of the investigation, we identified eight proteins that exhibited pronounced changes in their synthesis due to combined treatment. The data accumulated may shed light on molecular mechanisms underlying protective antiseptic action of HS and/or recombinant Hsp70 applied before LPS administration.     

Helix swapping leads to dimerization of the N-terminal domain of the c-type cytochrome maturation protein CcmH from Escherichia coli

In the process of cytochrome c maturation, heme groups are covalently attached to reduced cysteines of specific heme-binding motifs (CXXCH) in an apocytochrome c sequence. In Escherichia coli, the CcmH protein maintains apo-protein cysteines in a reduced state prior to heme attachment. We have purified and biophysically, as well as structurally characterized the soluble, N-terminal domain of E. coli CcmH that carries the functionally relevant LRCXXC-motif. In contrast to a recently presented structure of the homologous domain from Pseudomonas aeruginosa, the E. coli protein forms a tightly interlinked dimer by swapping its N-terminal helix between two monomers. We propose that an altered environment of the functional motif may help to discern between the two redox partners CcmG and apocytochrome c.     

Ecological description of the sodium chloride mineral springs in the Kirenga River basin and the upper reaches of the Lena River: 1. General characteristics of the springs and their hydrofauna

The aquatic microecosystems and their environment have been studied in 12 mineral springs located in the Cis-Baikal Depression and in the basin of the upper reaches of the Lena River (Eastern Siberia). The hydrochemical characteristics of the springs, originating from the Cambrian salt deposits, are given. Their total mineralization varies from 1.1 to 123.0 g/L and the water is sodium chloride. The soils formed under the influence of the mineral waters (“para-soils”) are described. The data on the composition and quantitative abundance of aquatic fauna are presented. Six types of macroinvertebrate communities are described. The communities where Turbellaria, Gastropoda, and Psychodidae dominate are recorded in weakly mineralized waters (<3 g/L). The communities where Chironomidae dominate are found in waters characterized both by low and high (up to 28 g/L) salinity. In springs with a water salinity of 2.5–11 g/L, communities characterized by the dominance and high biomass of amphipods Gammarus lacustris Sars. are formed. A unique type of community where Ephydridae larvae dominate (>97% of the biomass) is described for the concentrated brines in Ust’-Kutskii spring. Halophilic species of crustaceans are recorded in the meiofauna. The presence of Foraminifera (marine organisms) in the two studied springs attracts specific interest.     

Photoactivatable analogues of alpha-conotoxins GI and MI and their interaction with nicotinic acetylcholine receptor

Two photoactivatable analogues of alpha-conotoxin GI with the benzoylphenylalanine residue (Bpa) substituted for His10 or Tyr11 were synthesized using the method of solid-phase peptide synthesis. In addition, alpha-conotoxin MI was chemically modified by placing an azidobenzoyl or a benzoylbenzoyl photo label at N alpha of Gly1 or N epsilon of Lys10. All the photoactivatable analogues were purified by HPLC, their structures were confirmed by MALDI MS, and the label positions in their molecules were localized by MS of their trypsinolysis fragments. All the analogues interacted with the nicotinic acetylcholine receptor (AChR) from Torpedo californica as efficiently as the native alpha-conotoxins, with the differences in the inhibition constants being within one order of magnitude under the same conditions. [125I]Derivatives prepared from all the analogues retained the ability to be bound by AChR and were used in the photoinduced AChR cross-linking. All the AChR subunits were found to be cross-linked to the photoactivatable analogues, with the linking depending on both the chemical nature of label and its position in the alpha-conotoxin molecule.