Control of spatial cell attachment on carbon nanofiber patterns on polycarbonate urethane

A highly aligned pattern of carbon nanofibers (CNF) on polycarbonate urethane (PCU) for tissue engineering applications was created by placing a CNF-ethanol solution in 30 microm width copper grid grooves on top of PCU. In vitro results provided the first evidence that fibroblasts and vascular smooth muscle cells selectively adhered to the PCU regions. However, endothelial cells did not display a preference for adhesion to the CNF compared with PCU regions. Previous studies have shown selective adhesion of osteoblasts (bone-forming cells) on CNF compared with PCU regions. Thus, the present results suggest that CNF aligned on PCU may be useful substrates for the control of spatial cell attachment, criteria useful for the design of a wide range of tissue engineering materials, from orthopedic to vascular.     

A Novel Gene Cluster soxSRT Is Essential for the Chemolithotrophic Oxidation of Thiosulfate and Tetrathionate by Pseudaminobacter salicylatoxidans KCT001

Chemolithotrophic sulfur oxidation (Sox) in the α-proteobacterium Pseudaminobacter salicylatoxidans KCT001 was found to be governed by the gene cluster soxSRT–soxVWXYZABCD. Independent transposon-insertion mutations in the genes soxB, soxC, soxD, and also in a novel open reading frame (ORF), designated as soxT, afforded revelation of the entire sox locus of this bacterium. The deduced amino acid sequence of the novel ORF soxT comprised 362 residues and exhibited significant homology with hypothetical proteins of diverse origin, including a permease-like transport protein of Escherichia coli. Two contiguous ORFs, soxR and soxS, immediately preceded the soxT gene. The gene cluster soxSRT was located upstream of soxVWXYZABCD and was transcribed divergently with respect to the latter. Chemolithotrophic utilization of both thiosulfate and tetrathionate was observed to have been impaired in all of these Sox⁻ mutants, implicating the involvement of the gene cluster soxSRT–soxVWXYZABCD in the oxidation of both thiosulfate and tetrathionate. Pradosh Roy Deceased     

Enantioselective cyanoformylation of aldehydes catalyzed with solid base mediated chiral V(V) salen complexes

Polymeric and monomeric V(V) chiral salen complexes‐catalyzed enantioselective ethyl cyanoformylation of aldehydes using ethyl cyanoformate as a source of cyanide was accomplished in the presence of several basic cocatalysts viz., NaOH, KOH, basic Al₂O₃ and hydrotalcite. Excellent yield (>95%) of chiral ethyl cyanohydrincarbonate with high enantioselectivity up to 94% was achieved in 24–36 h when hydrotalcite was used as an additive. The polymeric catalyst 1 is more reactive than the monomeric catalyst 2 to produce chiral ethyl cyanohydrincarbonate in high optical purity. The chiral polymeric catalyst 1 and cocatalysts hydrotalcite and basic alumina used in this study were recoverable and recyclable several times with retention of its performance. Chirality, 2010. © 2009 Wiley‐Liss, Inc.     

Interaction of pea (Pisum sativum L.) lectins with rhizobial strains

Lectins from two varieties (PG-3 and LFP-48) of pea have been purified by affinity chromatography on Sephadex G-50. The specific activity increased by 23 and 25 folds, respectively. These lectins from both the varieties were found to be specific for mannose. The purified fluorescein isothiocyanate (FITC) – labelled lectins showed binding reaction with homologous as well as heterologous strains of Rhizobium spp. The results revealed that pea lectins are not highly specific to their respective rhizobia. Moreover, these lectins showed a greater stimulatory effect on homologous Rhizobium leguminosarum strains.     

Paternal imprinting of the SLC22A1LS gene located in the human chromosome segment 11p15.5

Prostate cancer is the most commonly diagnosed cancer in men and one of the leading causes of cancer deaths. There is strong genetic evidence indicating that a large proportion of prostate cancers are caused by heritable factors but the search for prostate cancer susceptibility genes has thus far remained elusive. TGFBR1*6A, a common hypomorphic variant of the type I Transforming Growth Factor Beta receptor, is emerging as a tumor susceptibility allele that predisposes to the development of breast, colon and ovarian cancer. The association with prostate cancer has not yet been explored. A total of 907 cases and controls from New York City were genotyped to test the hypothesis that TGFBR1*6A may contribute to the development of prostate cancer. TGFBR1*6A allelic frequency among cases (0.086) was slightly higher than among controls (0.080) but the differences in TGFBR1*6A genotype distribution between cases and controls did not reach statistical significance (p = 0.67). Our data suggest that TGFBR1*6A does not contribute to the development of prostate cancer.     

Enhanced production of poly (γ-glutamic acid) from <Emphasis Type="Italic">Bacillus licheniformis</Emphasis> NCIM 2324 in solid state fermentation

This work reports on the optimization of PGA production by Bacillus licheniformis NCIM 2324 in solid state fermentation (SSF). In the first step, the one factor-at-a-time method was used to investigate the effect of solid substrates, initial moisture content, pH, and additional carbon and nitrogen source on PGA production; subsequently, response surface methodology (RSM) was used to establish the optimum concentrations of the key nutrients for higher PGA production. In the second step, the effects of amino acids and TCA cycle intermediates on the production of PGA were studied. The final optimized medium gave a maximum yield of 98.64 ± 1.61 mg gds⁻¹ of PGA, which is significantly higher than that reported in the literature.     

Promoter characterization and regulation of expression of an imprinted gene SLC22A18AS

The SLC22A18/SLC22A18AS genes are a sense-antisense pair located at human chromosome segment 11p15.5. These genes are paternally imprinted: paternal alleles are silenced and maternal alleles are expressed. Although SLC22A18 is a well-characterized gene, very little is known regarding its antisense partner SLC22A18AS. We therefore sought to identify the potential cis-regulating elements including the promoter of this gene, differentially methylated regions (DMRs) and the translation of its putative ORF. Dual promoters (P1 and P2) were identified for this gene and both are devoid of consensus TATA and CCAAT boxes. However, the P1 promoter harbors a putative Sp1 binding site. Sp1 binds to the P1 promoter in vivo and positively regulates its activity. Promoter and CpG II island regions showed heavy methylation of CpG sites, but no DMRs were observed. Treatment of a non-SLC22A18AS expressing HuH7 cells with the methyltransferase inhibitor 5-aza-2'-deoxycytidine restored expression of this gene. The histone deacetylase (HDAC) inhibitor Trichostatin-A, on the other hand, failed to induce its expression. We suggest that the expression of this gene is methylation-dependent, but histone acetylation-independent. This gene was found to be translated with a cytoplasmic localization. The present data will help to understand the regulation of this gene and its role in tumorigenesis.     

Accurate detection of protein:ligand binding sites using molecular dynamics simulations

Accurate prediction of location of cavities and surface grooves in proteins is important, as these are potential sites for ligand binding. Several currently available programs for cavity detection are unable to detect cavities near the surface or surface grooves. In the present study, an optimized molecular dynamics based procedure is described for detection and quantification of interior cavities as well as surface pockets. This is based on the observation that the mobility of water in such pockets is significantly lower than that of bulk water. The algorithm efficiently detects surface grooves that are sites of protein-ligand and protein-protein interaction. The algorithm was also used to substantially improve the performance of an automated docking procedure for docking monomers of nonobligate protein-protein complexes. In addition, it was applied to predict key residues involved in the binding of the E. coli toxin CcdB with its inhibitor. Predictions were subsequently validated by mutagenesis experiments.