Hydrogen production by recombinant strains of <Emphasis Type="Italic">Rhodobacter sphaeroides</Emphasis> using a modified photosynthetic apparatus

Hydrogen production by recombinant strains of Rhodobacter sphaeroides pRK puf DD13 without a peripheral light-harvesting antenna complex and pRK puf ΔLM1 which is able to synthesize both antenna complexes, both of which were grown in conditions of nitrogen limitation, has been studied. The rate of hydrogen production depended on light intensity. At high cell concentration (0.91 g l⁻¹) of pRK puf DD13, rate was maximal at 2270 W m⁻² and was equal to 144.7 ml l⁻¹ h⁻¹ that evidences to an opportunity to increase the volume rate of hydrogen production by application of the strains with low content of pigments.     

TULA-family proteins: Jacks of many trades and then some

UBASH3/STS/TULA is a novel two-member family, which exerts several key regulatory effects in multiple cell types. UBASH3B/STS-1/TULA-2 is a highly active protein tyrosine phosphatase; its major target appears to be a specific regulatory site of protein tyrosine kinases of the Syk family, dephosphorylation of which inhibits Syk and Zap-70 kinases and suppresses receptor signaling mediated by these kinases. UBASH3A/STS-2/TULA exhibits substantial homology to UBASH3B/STS-1/TULA-2, but possesses only a small fraction of phosphatase activity of UBASH3B/STS-1/TULA-2, and thus, its regulatory effect may be based also on the phosphatase-independent mechanisms. Critical physiologic effects of these proteins have been demonstrated in T lymphocytes, platelets, stem cells, and other important cell types. These proteins have also been shown to play a key role in such pathologic conditions as autoimmunity, cancer, and thrombosis. The review focuses on the recent studies of this important family of cellular regulators.     

Localization of prophage SM of Pseudomonas aeruginosa in the chromosome of host cells

Pseudomonas aeruginosa PAO SM-prophage was localized on the chromosome between thr-9001 and pur-66 locuses on 42-43 min of chromosomal genetic map. The location of prophage was identified on the basis of prophage linkage with the above-mentioned markers and confirmed by the purine, hypoxanthine and threonine deletions in course of thermoinduction of SM cts6 prophage from lysogens. The decrease for two orders in lysogenization frequency of thr mutants by SM bacteriophage suggests the integration of SM prophage in these cells into some other region of chromosome.     

Transducing activity of the temperate SM bacteriophage of Pseudomonas aeruginosa

The temperate bacteriophage SM is not serologically related to the known transducing phages F116, G101, B3 of Pseudomonas aeruginosa. The strains with auxotrophic mutations within the wide ranges of the genetic map of P. aeruginosa strain PAO1 were used for studying the transducing activity of the SM phage. All of the 7 bacterial markers tested are transduced with SM phage grown on a prototrophic donor strain. The frequency of transduction of separate bacterial markers using the wild type SM phage is 2.3 to 4.6 X 10(-8). Linked ilv202+ - met28+ markers are cotransduced with SM phage at a frequency of about 1.5%.     

Inventing Engineered Organoids for end-stage liver failure patients

Journal of Molecular Histology - End-stage liver disease (ESLD) is a term used clinically in reference to a group of liver diseases with liver transplantation as the choice of treatment. Due to the...     

Chiral ureas with two electronegative substituents at 1-N: an unusual case of coexisting pyramidal and almost planar 1-N atoms in the same crystal

XRD studies of structure of N-acetoxy-N-methoxyurea and N,N-bis(methoxycarbonyl)-N-methoxyimide have revealed that in N-methoxy-N-X-ureas (X = OAc, Cl, OMe, N(+)C(5)H(5)) the additional shortening of N-OMe bond took place, which arising from an n(O(Me))-sigma*(N-X) anomeric orbital interaction. XRD studies of N-chloro-N-ethoxyurea crystal have revealed the presence of two kinds of anomeric nitrogen configuration in the O-N-Cl group in the form of a pyramidal configuration and a planar configuration for same 1-N nitrogen atom. XRD studies of N-4-chlorobenzoyloxy-N-ethoxyurea have revealed that the degree of pyramidality of the 1-N nitrogen in N-aroyloxy-N-alkoxyureas is tuned by orientation of benzoyl group with respect to the N-O bond, which in turn depends of size of N-alkoxy group.     

Identifying the neural circuitry of alcohol craving and relapse vulnerability

With no further intervention, relapse rates in detoxified alcoholics are high and usually exceed 80% of all detoxified patients. It has been suggested that stress and exposure to priming doses of alcohol and to alcohol-associated stimuli (cues) contribute to the relapse risk after detoxification. This article focuses on neuronal correlates of cue responses in detoxified alcoholics. Current brain imaging studies indicate that dysfunction of dopaminergic, glutamatergic and opioidergic neurotransmission in the brain reward system (ventral striatum including the nucleus accumbens) can be associated with alcohol craving and functional brain activation in neuronal systems that process attentional relevant stimuli, reward expectancy and experience. Increased functional brain activation elicited by such alcohol-associated cues predicted an increased relapse risk, whereas high brain activity elicited by affectively positive stimuli may represent a protective factor and was correlated with a decreased prospective relapse risk. These findings are discussed with respect to psychotherapeutic and pharmacological treatment options.     

Determination of the Substrate Specificity of Protein-tyrosine Phosphatase TULA-2 and Identification of Syk as a TULA-2 Substrate

TULA-1 (UBASH3A/STS-2) and TULA-2 (p70/STS-1) represent a novel class of protein-tyrosine phosphatases. Previous studies suggest that TULA-2 is sequence-selective toward phosphotyrosyl (Tyr(P)) peptides. In this work the substrate specificity of TULA-1 and -2 was systematically evaluated by screening a combinatorial Tyr(P) peptide library. Although TULA-1 showed no detectable activity toward any of the Tyr(P) peptides in the library, TULA-2 recognizes two distinct classes of Tyr(P) substrates. On the N-terminal side of Tyr(P), the class I substrates contain a proline at the Tyr(P)−1 position, a hydrophilic residue at the Tyr(P)−2 position, and aromatic hydrophobic residues at positions Tyr(P)−3 and beyond. The class II substrates typically contain two or more acidic residues, especially at Tyr(P)−1 to Tyr(P)−3 positions, and aromatic hydrophobic residues at other positions. At the C-terminal side of Tyr(P), TULA-2 generally prefers acidic and aromatic residues. The library screening results were confirmed by kinetic analysis of representative peptides selected from the library as well as Tyr(P) peptides derived from various Tyr(P) proteins. TULA-2 is highly active toward peptides corresponding to the Tyr(P)-323 and Tyr(P)-352 sites of Syk, and the Tyr(P)-397 site of focal adhesion kinase and has lower activity toward other Tyr(P) sites in these proteins. In glycoprotein VI-stimulated platelets, knock-out of the TULA-2 gene significantly increased the phosphorylation level of Syk at Tyr-323 and Tyr-352 sites and to a lesser degree at the Tyr-525/526 sites. These results suggest that Syk is a bona fide TULA-2 substrate in platelets.