Improved Electrochemical Analysis of Neuropathy Target Esterase Activity by a Tyrosinase Carbon Paste Electrode Modified by 1-Methoxyphenazine Methosulfate

A graphite-paste tyrosinase biosensor was improved by adding 1-methoxyphenazine methosulfate as a mediator. Mediator modification enhanced sensitivity to phenol 4-fold and long-term stability 3-fold. Phenol could be detected at 25 nM (S/N=2) using an Ag/AgCl reference electrode. The biosensor was used to measure the activity of a toxicologically significant enzyme, neuropathy target esterase (NTE), which yields phenol by hydrolysis of the substrate, phenyl valerate. Using the new biosensor, blood and brain NTE inhibition by organophosphorus (OP) compounds with different neuropathic potencies were well correlated (r=0.990, n=7), supporting the use of blood NTE as a biochemical marker of exposure to neuropathic OP compounds.     

Cheap and Long‐Life Reusable Polymer for Asymmetric Organozinc Catalysis Based on Camphor‐Derived Hydroxyamides

Polystyrene grafted with a chiral zinc‐complexing camphor‐derived N,N‐disubstituted hydroxyamide is proposed as a new type of functional polymer of high reusability for the development of sustainable organozinc‐catalyzed asymmetric reactions. The main goal of this new functional polymer is the ease of the hydroxyamide‐moiety preparation (cheap chiral ligand obtained straightforwardly from an enantiopure starting material coming from the chiral pool), as well as its chemical robustness when compared with other related zinc‐complexing functional groups. The latter allows the polymer to be active after multiple applications, without significant loss of its catalytic activity. This fact is exemplified by the design and preparation of a polymer functionalized with a bis(hydroxyamide) proved previously as active in the homogeneous enantioselective addition of diethylzinc to aldehydes. The result is a cheap functional polymer with a very high reusability (the enantioselectivity and chemical yield are maintained practically constant after 20 applications). Additionally, a methodology for the multicycle use of these functional polymers is presented. Chirality, 2012. © 2012 Wiley Periodicals, Inc.     

Distribution of ichthyoplankton in the eastern Peter the Great Bay,Sea of Japan,in June and July of 2007

Comparison of the results of ichthyoplankton surveys conducted at 97 stations in the eastern part of the Peter the Great Bay of the Sea of Japan, in June–July 2007 with the similar research data of the 1950s shows that at present, as was the case 50 years ago, flatfish eggs belonging mainly to the yellowfin sole Limanda aspera and brown sole Pleuronectes herzensteini prevail in the local ichthyoplankton (up to 86%). The highest concentrations of these species’ eggs were recorded in the Vostok Bay and Strelok Bay. The spawning activity of flatfish in 2007 is found to be lower than in the mid 1900s, but the significance of the eastern part of the Peter the Great Bay for flatfish reproduction remains large. The importance of long-term monitoring in this area, which is being subjected to steadily growing anthropogenic impacts, is also proven.     

Induction of catalytic activity of plasminogen by monoclonal antibody IV-Ic in the presence of divalent metal cations and α2-antiplasmin

Investigation of the influence of divalent metal cations on the induction of plasminogen catalytic activity by monoclonal antibody IV-Ic showed that the presence of metal cations in the reaction medium changes the induction by slowing down or accelerating the process. Ions of Zn²⁺, Mn²⁺, and Cu²⁺ completely inhibit activation. Ions of Co²⁺ and Ni²⁺ decrease the rate of the first and second phases of the reaction more than 2 times. Ca²⁺ ions do not have any effect on the activation rate. Ions of Mg²⁺, Ba²⁺, and Sr²⁺ increase the rate of the first phase of the reaction by 1.5, 2.0, and 2.0 times and the rate of the second phase by 2.0, 3.8, and 4.7 times, correspondingly. Sr²⁺ ions have the strongest stimulating effect on plasminogen activation by monoclonal antibody IV-Ic. Investigation of the dose dependent effect of Sr²⁺ on the rate of plasminogen activation by monoclonal antibody IV-Ic showed stimulating effect of Sr²⁺ at concentrations from 0.1 to 1.0 mM with half maximum at 0.6 mM. However, Sr²⁺ ions do not affect amidolytic activity of plasmin and activation of plasminogen by streptokinase. Sr²⁺ ions also do not affect monoclonal antibody IV-Ic binding to plasminogen. The effect of Sr²⁺ is specific and mediated by the IV-Ic component. The presence of metal cations affects conformational changes in the process of active site formation. Metal cations also affect structure of the plasminogen molecule active site in the complex with monoclonal antibody IV-Ic and enzyme-substrate interaction. The effect of α₂-antiplasmin on the induction of plasminogen catalytic activity by monoclonal antibody IV-Ic in range of concentrations from 5 to 30 nM has been studied. α₂-Antiplasmin at concentration 30 nM almost completely inhibits induction of plasminogen catalytic activity by monoclonal antibody IV-Ic at the ratio plasminogen/α₂-antiplasmin of 3:1. This can be explained by competition of α₂-antiplasmin and monoclonal antibody IV-Ic for the lysine-binding sites of plasminogen and inhibition of the active center in activated complex plasminogen*—mAB IV-Ic. Divalent metal cations and α₂-antiplasmin are important factors in induction of plasminogen catalytic activity by monoclonal antibody IV-Ic. Published in Russian in Biokhimiya, 2006, Vol. 71, No. 6, pp. 778–785.     

Larvae and Juveniles of the Genus Liparis (Pisces: Liparidae) from the Northwestern Sea of Japan

Larvae and juveniles of Liparis ochotensis, L. latifrons, L. tartaricus, L.brashnikovi, and L. kusnetzovi (Liparidae) are described for the first time based on ichthyoplankton catches carried out in the northwestern Sea of Japan in the decade 1992–2002. Our earlier published data on the larval development of L. agassizii and juveniles of L. punctulatus are supplemented. It is shown that larval development in the Liparis includes a planktonic stage. The larvae of different species turn into juveniles at a different lengths: under 15 mm in the case of littoral species and at about or over 20 mm in the case of sublittoral species. The major morphological characteristics of larvae of different Liparis species—body height and shape, pelvic disk length, preanal length, presence of a notch in the dorsal fin, pigmentation pattern, and others—have been distinguished. Original illustrations of larvae and juveniles are provided.     

Peculiarities of early ontogenesis of the tubenose poacher, <Emphasis Type="Italic">Pallasina barbata</Emphasis> steindachner, 1876 (Pisces,Agonidae) from Peter the Great Bay (Sea of Japan)

Based on the analysis of original material (52 specimens of Pallasina barbata larvae and juveniles), sampled in the Peter the Great Bay (Sea of Japan) from 1992 to 2006, the ontogenetic stages of this species were described for the first time. It is shown that P. barbata has a planktonic larval stage in its development. The major morphologic features that are typical for larvae and juveniles during their development were revealed. It was shown that snout length, head length and pectoral fin size are increased with growth; at the same time body height and eye diameter are decreased, and the nature of larval pigmentation is changed. The main differences between P. barbata and close species are shown. Original illustrations of larvae and juvenile are provided.     

Role of A-chain in functioning of the active site of human α-thrombin

This review summarizes current data suggesting that A-chain of the human alpha-thrombin molecule plays a role of allosteric effector in catalytic reactions with various substrates. Special attention is paid to the relationship between A-chain structure and catalytic activity of thrombin. The existence of this relationship is based on studies of natural mutation of A-chain of the alpha-thrombin molecule. Use of molecular and essential dynamics confirmed the role of A-chain in changes of conformation and catalytic properties of this enzyme; these changes involve residues located in the specificity sites and some inserting loops. Current knowledge on structure and properties of thrombin can be used for the development of new antithrombin agents.     

Molecular characterization of Streptococcus pneumoniae,particularly serotype19A/ST320, which emerged in Krasnoyarsk,Russia

Streptococcus pneumoniae , a common human pathogen, colonizes the nasopharynx and causes diseases including acute otitis media (AOM). Herein, pneumococcal serotype distributions in children before and after PCV7 vaccination and in patients with pneumococcal disease in Siberian Russia (Krasnoyarsk) are reported. Analyses included antimicrobial susceptibility testing, sequence typing (ST), pulsed field gel electrophoresis, virulence‐related surface protein gene (VSG) typing with novel primers and structural analysis by scanning electron microscopy. In healthy children (HC) prior to administration of PCV7, drug‐susceptible serotype23F/ST1500 was a major pneumococcal genotype. In the PCV7 trial, multidrug‐resistant serotype19A/ST320 emerged in vaccinees after PCV7, exhibiting a PCV7‐induced serotype replacement. Multidrug‐resistant serotype19A/ST320 was evident in patients with AOM. Community‐acquired pneumonia (CAP) isolates showed genetic similarities to the AOM (ST320) genotype, constituting a common non‐invasive AOM–CAP group. In contrast, meningitis isolates were more divergent. Overall, 25 ST types were identified; five (20%) of which were Krasnoyarsk‐native. Regarding VSGs, PI‐1 (rlrA /rrgB ), PI‐2 (pitA /B ), psrP and cbpA were present at 54.3%, 38.6%, 48.6%, and 95.7%, respectively, with two major VSG content types, PI‐1^?/PI‐2^?/psrP ⁺/cbpA ⁺ and PI‐1⁺/PI‐2⁺/psrP ^‐/cbpA ⁺, being found for HC and non‐invasive diseases, respectively. A major clone of serotype19A/ST320 (PI‐1⁺/PI‐2⁺) produced the longest pneumococcal wire (pilus) structures in colonies. ST1016 (PI‐1^?/PI‐2^?) in HC had HEp‐2 cell‐adherent pili. These results suggest that serotype19A/ST320 and related genotypes, with the VSG content type PI‐1⁺/PI‐2⁺/psrP ^?/cbpA ⁺, emerged in vaccinees after PCV7 in Siberia, accompanying diseases in non‐vaccinated children, and that some genotypes (serotypes19A/ST320 and 18/ST1016) produced novel pneumococcal structures, predicting their roles in colony formation and adherence.