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41.
Balaban NP Mardanova AM Sharipova MR Gabdrakhmanova LA Sokolova EA Garusov AV Milgotina EI Rudenskaya GN Leshchinskaya IB 《Biochemistry. Biokhimii?a》2003,68(11):1217-1224
The culture filtrate of Bacillus intermedius 3-19 was used for isolation by chromatography on CM-cellulose and Mono S columns of a proteinase that is secreted during the late stages of growth. The enzyme is irreversibly inhibited by the inhibitor of serine proteinases diisopropyl fluorophosphate, has two pH optima (7.2 and 9.5) for casein hydrolysis and one at pH 8.5 for Z-Glu-pNA hydrolysis. The molecular weight of the enzyme is 26.5 kD. The K(m) for Z-Glu-pNA hydrolysis is 0.5 mM. The temperature and pH dependences of the stability of the proteinase were studied. The enzyme was identified as glutamyl endopeptidase 2. The N-terminal sequence (10 residues) and amino acid composition of the enzyme were determined. The enzyme hydrolyzes Glu4-Gln5, Glu17-Asp18, and Cys11-Ser12 bonds in the oxidized A-chain of insulin and Glu13-Ala14, Glu21-Arg22, Cys7-Gly8, and Cys19-Gly20 bonds in the oxidized B-chain of insulin. 相似文献
42.
Diuzhikova NA Sokolova NE Vaĭdo AI Shiriaeva NV Lopatina NG Levkovich IuI 《Zhurnal vysshe? nervno? deiatelnosti imeni I P Pavlova》2001,51(4):511-513
Quantitative characteristics (the area and number of chromocenters) of the interphase C-heterochromatin in the nuclei of pyramidal neurons of the midbrain reticular formation, sensorimotor cortex, and hippocampus (CA3) of rat strains with different genetically determined excitability were studied in the normal state of the animals and after exposure to a short-term emotional pain stress. The results indicate a relationship between the excitability of the nervous system and structural-functional state of the neuronal interphase heterochromatin. The role of cytogenetic features of different brain structures in the CNS functioning and behavior and their relation with genetically determined excitability of the nervous system are discussed. 相似文献
43.
44.
Nazina TN Grigor'ian AA Sue KF Sokolova DSh Novikova EV Turova TP Poltaraus AB Beliaev SS Ivanov MV 《Mikrobiologiia》2002,71(1):103-110
A diverse and active microbial community in the stratal waters of the Daqing oil field (China), which is exploited with the use of water-flooding, was found to contain aerobic chemoheterotrophic bacteria (including hydrocarbon-oxidizing ones) and anaerobic fermentative, sulfate-reducing, and methanogenic bacteria. The aerobic bacteria were most abundant in the near-bottom zones of injection wells. Twenty pure cultures of aerobic saprotrophic bacteria were isolated from the stratal waters. Under laboratory conditions, they grew at temperatures, pH, and salinity values typical of the stratal water from which they were isolated. These isolates were found to be able to utilize crude oil and a wide range of hydrocarbons, fatty acids, and alcohols. Phylogenetic analysis carried out with the use of complete 16S rRNA sequences showed that the isolates could be divided into three major groups: gram-positive bacteria with a high and a low G + C content of DNA and gram-negative bacteria of the gamma-subclass of the Proteobacteria. Gram-positive isolates belonged to the genera Bacillus, Brevibacillus, Rhodococcus, Dietzia, Kocuria, Gordonia, Cellulomonas, and Clavibacter. Gram-negative isolates belonged to the genera Pseudomonas and Acinetobacter. In their 16S rRNA sequences, many isolates were similar to the known microbial species and some probably represented new species. 相似文献
45.
Gabdrakhmanova LA Balaban NP Sharipova MR Tokmakova IuS Sokolova EA Rudenskaia GN Leshchinskaia IV 《Mikrobiologiia》2002,71(3):323-329
The effect of some components of cultivation medium on the growth of the streptomycin-resistant Bacillus intermedius strain 3-19 and on the production of glutamyl endopeptidase was investigated using factorial experimental design, which allowed the concentrations of peptone and inorganic phosphate to be optimized for the maximum production of the enzyme. Experiments with different peptones and casamino acids showed that the enzyme production is maximum with peptone 3 of plant origin. The addition of casamino acids or amino acids to the peptone-containing cultivation medium inhibited the production of glutamyl endopeptidase. 相似文献
46.
In an attempt to compare the regulation of chick connexin43 channels to those of mammalian connexin43, we found that the nucleotide sequence reported for chick connexin43 differs from that of the chick connexin gene by two codons that had been entered as histidine49 (H49) and valine50 (V50) (accession no. M29003), but are in fact glutamine49 (Q49) and serine50 (S50). Neuro2A cells were transfected with corrected wild-type (Q49/S50) chick connexin43 (accession no. AF233738), the double-replacement Q49H/S50V connexin43, or the single replacement of Q49H or S50V. All clones had gap junctions in membrane based on immunocytochemistry and immunoblots of the triton-resistant membrane fraction. Wild-type transfectants had three conductance states with a predominant channel conductance of 85 ±5 pS. Cells producing the Q49H-Cx43 or the double-replacement Q49H/S50V-Cx43 protein had no detectable connexin43 channels. In contrast, cells expressing S50V-Cx43 gap junctions had channels with reduced conductances (75 ±8 pS) compared to wild-type controls. Low or high pH of the bathing solution had no effect on the Q49H-Cx43 channels. We conclude that glutamine49 is important for channel function, and replacement of this residue with histidine most likely distorts secondary structure of the first extracellular loop, possibly by changing the orientation of conserved cysteines, and this inhibits channel function. The S50V substitution may also cause similar but less severe structural changes. 相似文献
47.
Maslova MV Maklakova AS Sokolova NA Ahmarin IP Goncharenko EN Krushinskaia IaV 《Rossi?skii fiziologicheski? zhurnal imeni I.M. Sechenova / Rossi?skaia akademiia nauk》2002,88(2):184-190
Ante- and postnatal acute hypoxia significantly aggravated the postnatal development. The posthypoxic behaviour patterns included hyperactivity and training ability inhibition typical for the attention deficit syndrome. A preventive injection of peptide constellation significantly improved the posthypoxic postnatal development and abolished the most of the negative modifications of behavioural patterns. 相似文献
48.
Darenskaia NG Korotkevich AO Grinev MP Sokolova IK Tsvetkov VI 《Radiatsionnaia biologiia, radioecologiia / Rossi?skaia akademiia nauk》2000,40(1):37-42
The damaging effect of gamma-neutron radiation over a wide neutron-energy range, with average values of 0.37 and 1.2 MeV, and that of electrons with an average electron energy of 25 MeV have been compared in dogs and two monkey species exposed to a broad range of supralethal doses. An analysis of absorbed dose distribution in critical organs and systems has shown the highest effect of gamma-neutron radiation with an average neutron energy of 1.2 MeV. With severity of early clinical manifestations of damage as a criterion, electrons have appeared the most effective. The radiosensitivity of animals grew in the order as follows: dog-->M. fascicularis-->P. hamadryas. 相似文献
49.
50.
Agata Rekas Robert B. Knott Anna Sokolova Kevin J. Barnham Keyla A. Perez Colin L. Masters Simon C. Drew Roberto Cappai Cyril C. Curtain Chi L. L. Pham 《European biophysics journal : EBJ》2010,39(10):1407-1419
Inclusions of aggregated α-synuclein (α-syn) in dopaminergic neurons are a characteristic histological marker of Parkinson’s
disease (PD). In vitro, α-syn in the presence of dopamine (DA) at physiological pH forms SDS-resistant non-amyloidogenic oligomers.
We used a combination of biophysical techniques, including sedimentation velocity analysis, small angle X-ray scattering (SAXS)
and circular dichroism spectroscopy to study the characteristics of α-syn oligomers formed in the presence of DA. Our SAXS
data show that the trimers formed by the action of DA on α-syn consist of overlapping worm-like monomers, with no end-to-end
associations. This lack of structure contrasts with the well-established, extensive β-sheet structure of the amyloid fibril
form of the protein and its pre-fibrillar oligomers. We propose on the basis of these and earlier data that oxidation of the
four methionine residues at the C- and N-terminal ends of α-syn molecules prevents their end-to-end association and stabilises
oligomers formed by cross linking with DA-quinone/DA-melanin, which are formed as a result of the redox process, thus inhibiting
formation of the β-sheet structure found in other pre-fibrillar forms of α-syn. 相似文献