Molecular cloning and expression of a novel trehalose synthase gene from Enterobacter hormaechei

<p>Abstract</p> <p>Background</p> <p>Trehalose synthase (TreS) which converts maltose to trehalose is considered to be a potential biocatalyst for trehalose production. This enzymatic process has the advantage of simple reaction and employs an inexpensive substrate. Therefore, new TreS producing bacteria with suitable enzyme properties are expected to be isolated from extreme environment.</p> <p>Results</p> <p>Six TreS producing strains were isolated from a specimen obtained from soil of the Tibetan Plateau using degenerate PCR. A novel <it>treS </it>gene from <it>Enterobacter hormaechei </it>was amplified using thermal asymmetric interlaced PCR. The gene contained a 1626 bp open reading frame encoding 541 amino acids. The gene was expressed in <it>Escherichia coli</it>, and the recombinant TreS was purified and characterized. The purified TreS had a molecular mass of 65 kDa and an activity of 18.5 U/mg. The optimum temperature and pH for the converting reaction were 37°C and 6, respectively. Hg²⁺, Zn²⁺, Cu²⁺and SDS inhibited the enzyme activity at different levels whereas Mn²⁺showed an enhancing effect by 10%.</p> <p>Conclusion</p> <p>In this study, several TreS producing strains were screened from a source of soil bacteria. The characterization of the recombinant TreS of <it>Enterobacter hormaechei </it>suggested its potential application. Consequently, a strategy for isolation of TreS producing strains and cloning of novel <it>treS </it>genes from natural sources was demonstrated.</p

Lower Bounds of Concurrence for Tripartite Quantum Systems

We derive an analytical lower bound for the concurrence of tripartite quantum mixed states. A functional relation is established relating concurrence and the generalized partial transpositions.Comment: 10 page

Poly[[aqua-μ6-benzene-1,2,3-tricarboxyl­ato-μ3-hydroxido-dizinc] hemihydrate]

In the title compound, {[Zn2(C9H3O6)(OH)(H2O)]·0.5H2O}n, there are three independent ZnII atoms present; two are located on special positions, viz a twofold rotation axis and an inversion centre, and the third is located in a general position. The ZnII atom on the inversion centre is six-coordinated by four O atoms from four different benzene-1,2,3-tricarboxyl­ate anions and two OH− anions. The ZnII atom located on a twofold axis is four coordinated by two O atoms from two different benzene-1,2,3-tricarboxyl­ate anions and two OH− anions. The third ZnII atom, located in a general position, is five coordinated by three O atoms from three different benzene-1,2,3-tricarboxyl­ate anions, one OH− anion and one water mol­ecule. Each benzene-1,2,3-tricarboxyl­ate anion bridges six ZnII atoms, and the OH− anion bridges three ZnII atoms, resulting in the formation of a three-dimensional framework. A series of O—H⋯O hydrogen bonds involving the benzene-1,2,3-tricarboxyl­ate anions, the OH− anion and the coordinating and the two water solvent mol­ecules further stablize the crystal structure. The two solvent water molecules show occupancies of 0.5 and 0.25

Expression of COX-2 and Bcl-2 in primary fallopian tube carcinoma: correlations with clinicopathologic features

The aim of this study was to evaluate the expression of COX-2 and Bcl-2 in primary fallopian tube carcinoma (PFTC), as well as their correlations with clinicopathologic features. We studied a cohort of 33 patients with a pathological diagnosis of PFTC. Thirty normal tubal tissues used for controls were obtained from patients diagnosed with uterine myomas. Expression analysis for COX-2 and Bcl-2 was performed using the immunohistochemical technique. The rate of preoperative diagnosis was 18.2%. With a median survival of 61.0 months (95% CI: 43.2 to 78.8 months), the estimated five-year overall survival rate in the 33 patients was 39.0%. Increased expression of COX-2 and Bcl-2 was observed in tumor specimens compared to normal controls (p = 0.026; p = 0.003). The expression rate of COX-2 in node-positive tumors was significantly higher than that of node-negative tumors (p = 0.024). Moreover, the expression rate of COX-2 was statistically significantly higher in patients with infiltration through the serosa (p = 0.019). Positive significant associations were observed between Bcl-2 staining index and FIGO stage (p = 0.015), and between Bcl-2 staining and lymph node metastasis (p = 0.010). There was a significant correlation between COX-2 expression and Bcl-2 staining index (r = 0.517, p = 0.002). We conclude that COX-2 and Bcl-2 may potentially be useful prognostic markers for PFTC. The exact molecular mechanism for correlations between COX-2 and Bcl-2 remains to be elucidated. (Folia Histochemica et Cytobiologica 2011, Vol. 49, No. 3, 389&#8211;397

Separability of rank two quantum states on multiple quantum spaces

Explicit sufficient and necessary conditions for separability of $N$-dimensional rank two multiparty quantum mixed states are presented. A nonseparability inequality is also given, for the case where one of the eigenvectors corresponding to nonzero eigenvalues of the density matrix is maximally entangled.Comment: 10 pages, Late

Macroscopic Quantum Tunnelling in Rotating Bose-Einstein Condensates

In this paper we investigate the macroscopic quantum tunnelling and the phase coherence property of the rotating Bose-Einstein condensates in both static and dynamic cases by using the mean field theory.Comment: 10 pages, 1 figure, submitted to Phys.Rev.