Enzymes of SPZ7 phage: Isolation and properties

Bacteriophage enzyme preparations exolysin and endolysin were studied. Exolysin (a phage-associated enzyme) was obtained from tail fraction and endolysin from phage-free cytoplasmic fraction of disintegrated Salmonella enteritidis cells. A new method for purification of these enzymes was developed, and their molecular masses were determined. The main catalytic properties of the studied enzymes (pH optimum and specificity to bacterial substrates) were found to be similar. Both enzymes lyse Escherichia coli cells like chicken egg lysozyme, but more efficiently lyse S. enteritidis cells and cannot lyse Micrococcus luteus, a good substrate for chicken egg lysozyme. Similar properties of exolysin and endolysin suggest that these enzymes are structurally similar or even identical.     

Affine sorbent with typtophil-threonil-tirosine for binding immunoglobulin G: sorption characteristics and aspects of practical application

New chromatographic material based on tryptophil-threonil-tirosine was prepared. This sorbent effectively binds human, sheep, goat and cow immunoglobulins G. New sorbent shows high selectivity for removing immunoglobulins from blood plasma. Effective sorption capacity is 15-25 mg of immunoglobulin G per ml of matrix. Optimal method of covalent attachment ligand to polysaccharide matrix allows achieving high stability of the sorbents in terms of use and storage. This sorbent can be used in medicine and biotechnology.     

Bacteriolytic enzymes from the blood plasma of the sheep

Bacteriolytic factors from the blood plasma of healthy sheep have been studied. Three enzymes not described earlier in the literature have been identified and characterized. Two enzymes exhibit activity toward Escherichia coli and have molecular weights of 15 ± 2 kDa. The third enzyme that exhibits activity toward E. coli and Micrococcus luteus has a molecular weight of 34 ± 4 kDa. The kinetic parameters of bacterial lysis for all enzymes have been determined; in particular, optimal pH values for each of the substrates used have been found. For the identification of the enzymes, trypsinolysis and a mass-spectroscopic study of fragments have been carried out. The results were compared with the data on sheep proteins available in the Swiss-Prot, NCBI, and MSDB databases.     

Interaction of laser plasmas with noble gases

The interaction of a noble gas jet (Xe, Kr, He) with a laser plasma at a distance of ～1 cm from a solid target (Mg, (CH₂)_n, LiF, or CF₄) was studied for the first time. The line spectra that were excited in the course of charge exchange of multicharged ions with noble gas atoms in the interaction region were recorded. A clean (debris-free) soft X-ray source excited by laser pulses focused into a xenon jet was designed and investigated.     

Entrapping of Tyrosinase in a System of Reverse Micelles

The enzymatic activity of tyrosinase was studied both in aqueous and organic media. In the latter case tyrosinase was entrapped in a system of reverse micelles of Aerosol OT in octane. At hydration degree 25, when the inner cavity of the reverse micelles was comparable with the size of a tetrameric tyrosinase form known for aqueous solutions, an optimum level of catalytic activity was observed. Another peak of catalytic activity of tyrosinase was observed at hydration degree 12, when the size of the inner cavity of the reverse micelles was consistent with a monomeric form of tyrosinase. Thus, the system of reverse micelles can be exploited as a medium for the investigation of the monomeric form of tyrosinase, which is unstable in aqueous solution.     

L1 (LINE-1) retrotransposable elements provide a "fossil" record of the phylogenetic history of murid rodents

The single most difficult problem in phylogenetic analysis is deciding whether a shared taxonomic character is due to common ancestry or one that appeared independently due to convergence, parallelism, or reversion to an ancestral state. Mammalian L1 retrotransposons undergo periodic amplifications in which multiple copies of the elements are interspersed in the genome. Because these elements apparently are transmitted only by inheritance and are retained in the genome, a shared L1 amplification event can only be an inherited ancestral character. We propose that L1 amplification events can be an excellent tool for analyzing mammalian evolution and demonstrate here how we addressed several refractory problems in rodent systematics using L1 DNA as a taxonomic character.      

Engineering biocatalytic systems in organic media with low water content

The use of organic media in biocatalysis stems from the fact that in many cases biocatalytic processes can hardly be conducted (if at all) in aqueous solutions because of extremely low solubilities of substrates and/or unfavorable shift of the reaction equilibrium in water. The growing interest in this biotechnological area that has sprung up over the past few years has resulted in various approaches to enzyme stabilization against organic solvents. Thus, the main goal of the present review is to formulate a comprehensive classification of numerous successful nonaqueous biocatalytic systems based on a few fundamental principles. Typical examples are considered, along with the advantages and drawbacks inherent in each of the approaches discussed.     

The neuroleptic activity of haloperidol increases after its solubilization in surfactant micelles. Micelles as microcontainers for drug targeting

It has been suggested to use surfactant micelles as microcontainers for increasing the efficiency of neuroleptic targeting from blood flow into the brain. The neuroleptic action of haloperidol, intraperitoneally injected into mice in micellar solution of non-ionic block copolymer surfactant (pluronic P-85) in water, increased several-fold if compared with that observed for haloperidol aqueous solution. Incorporation of brain-specific antibodies into haloperidol-containing micelles resulted in additional drastic increase (more than by 2 orders of magnitude) in the drug effect.     

DNA methylation-associated colonic mucosal immune and defense responses in treatment-na?ve pediatric ulcerative colitis

Inflammatory bowel diseases (IBD) are emerging globally, indicating that environmental factors may be important in their pathogenesis. Colonic mucosal epigenetic changes, such as DNA methylation, can occur in response to the environment and have been implicated in IBD pathology. However, mucosal DNA methylation has not been examined in treatment-naïve patients. We studied DNA methylation in untreated, left sided colonic biopsy specimens using the Infinium HumanMethylation450 BeadChip array. We analyzed 22 control (C) patients, 15 untreated Crohn’s disease (CD) patients, and 9 untreated ulcerative colitis (UC) patients from two cohorts. Samples obtained at the time of clinical remission from two of the treatment-naïve UC patients were also included into the analysis. UC-specific gene expression was interrogated in a subset of adjacent samples (5 C and 5 UC) using the Affymetrix GeneChip PrimeView Human Gene Expression Arrays. Only treatment-naïve UC separated from control. One-hundred-and-twenty genes with significant expression change in UC (> 2-fold, P < 0.05) were associated with differentially methylated regions (DMRs). Epigenetically associated gene expression changes (including gene expression changes in the IFITM1, ITGB2, S100A9, SLPI, SAA1, and STAT3 genes) were linked to colonic mucosal immune and defense responses. These findings underscore the relationship between epigenetic changes and inflammation in pediatric treatment-naïve UC and may have potential etiologic, diagnostic, and therapeutic relevance for IBD.