Jankowitsch F.,Mannheim University of Applied Sciences |
Schwarz J.,Mannheim University of Applied Sciences |
Ruckert C.,Bielefeld University |
Gust B.,University of Tubingen |
And 5 more authors.
Journal of Bacteriology | Year: 2012
Streptomyces davawensis JCM 4913 synthesizes the antibiotic roseoflavin, a structural riboflavin (vitamin B2) analog. Here, we report the 9,466,619-bp linear chromosome of S. davawensis JCM 4913 and a 89,331-bp linear plasmid. The sequence has an average G+C content of 70.58% and contains six rRNA operons (16S-23S-5S) and 69 tRNA genes. The 8,616 predicted proteincoding sequences include 32 clusters coding for secondary metabolites, several of which are unique to S. davawensis. The chromosome contains long terminal inverted repeats of 33,255 bp each and atypical telomeres. Sequence analysis with regard to riboflavin biosynthesis revealed three different patterns of gene organization in Streptomyces species. Heterologous expression of a set of genes present on a subgenomic fragment of S. davawensis resulted in the production of roseoflavin by the host Streptomyces coelicolor M1152. Phylogenetic analysis revealed that S. davawensis is a close relative of Streptomyces cinnabarinus, and much to our surprise, we found that the latter bacterium is a roseoflavin producer as well. © 2012, American Society for Microbiology.
Rehdorf J.,University of Greifswald |
Rehdorf J.,BRAIN AG |
Behrens G.A.,University of Greifswald |
Nguyen G.-S.,University of Greifswald |
And 2 more authors.
Applied Microbiology and Biotechnology | Year: 2012
An esterase from Pseudomonas putida JD1 (PPE) was successfully cloned, actively expressed in Escherichia coli, and characterized. It was discovered that PPE is more active towards short-chain esters, hydrolyzed δ-valerolactone, and ε-caprolactone and was most active at 37°C and pH 8. After purification to homogeneity by Ni-NTA-assisted affinity chromatography, the kinetic parameters K M and k cat were determined for p-nitrophenyl acetate and butyrate, respectively, showing better catalytic efficiency for hydrolysis of the acetate residue. Investigation of the protein sequence revealed not only the classical catalytic triad for carboxylesterases, additionally the interesting GGG(A)X-motif, which is associated to activity towards tertiary alcohols, was found. Indeed, enzymatic activity was shown for a set of different tertiary alcohols with enantioselectivities up to E∈=∈20, suggesting PPE to be a promising biocatalyst. In addition, PPE also hydrolyzed 4-hydroxyphenyl acetate, the product of a Baeyer-Villiger monooxygenase-catalyzed oxidation of 4-hydroxyacetophenone with a specific activity of 34.36 U/mg suggesting a physiological role in P. putida JD1. © 2011 Springer-Verlag.
Aquila M.,University of Ferrara |
Aquila M.,BRAIN AG |
Benedusi M.,University of Ferrara |
Fasoli A.,University of Ferrara |
And 2 more authors.
PLoS ONE | Year: 2015
The phototransduction enzymatic cascade in cones is less understood than in rods, and the zebrafish is an ideal model with which to investigate vertebrate and human vision. Therefore, here, for the first time, the zebrafish green cone photoresponse is characterized also to obtain a firm basis for evaluating how it is modulated by exogenous molecules. To this aim, a powerful method was developed to obtain long-lasting recordings with low access resistance, employing pressure-polished patch pipettes. This method also enabled fast, efficient delivery of molecules via a perfusion system coupled with pulled quartz or plastic perfusion tubes, inserted very close to the enlarged pipette tip. Sub-saturating flashes elicited responses in different cells with similar rising phase kinetics but with very different recovery kinetics, suggesting the existence of physiologically distinct cones having different Ca2+ dynamics. Theoretical considerations demonstrate that the different recovery kinetics can be modelled by simulating changes in the Ca2+-buffering capacity of the outer segment. Importantly, the Ca2+-buffer action preserves the fast response rising phase, when the Ca2+-dependent negative feedback is activated by the light-induced decline in intracellular Ca2+. © 2015 Aquila et al.This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Kueper T.,Symrise GmbH and Co. KG |
Krohn M.,BRAIN AG |
Haustedt L.O.,AnalytiCon Discovery GmbH |
Hatt H.,Ruhr University Bochum |
And 2 more authors.
Experimental Dermatology | Year: 2010
During the past years the topic sensitive skin became one of the most important fields in dermatology. The tremendous interest is based on several studies showing that about 50% of the population declares to have sensitive skin. The human thermoreceptor hTRPV1 was previously identified to contribute to this skin condition while facilitating neurogenic inflammation leading to hyperalgesia. Furthermore, skin sensitivity towards capsaicin, a natural activator of TRPV1, was shown to correlate with sensitive skin. In a screening campaign based on recombinant HEK293-cells stably transfected with hTRPV1, the selective antagonist trans-4-tert-butylcyclohexanol was identified. This antagonist is able to inhibit capsaicin-induced hTRPV1 activation with an IC50 value of 34±5μm tested in HEK293-cells as well as in electrophysiological recordings performed in oocytes expressing hTRPV1. Strikingly, in a clinical study with 30 women using topical treatment with o/w emulsions containing 31.6 ppm capsaicin, we were able to show that 0.4% of this inhibitor significantly reduces capsaicin-induced burning (P<0.0001) in vivo. Thus trans-4-tert-butylcyclohexanol has the potential as a novel bioactive for the treatment of sensitive skin. © 2010 John Wiley & Sons A/S.
Liebeton K.,BRAIN AG |
Lengefeld J.,ETH Zurich |
Eck J.,BRAIN AG
Journal of Biotechnology | Year: 2014
Bacillus subtilis is a commonly used host for the heterologous expression of genes in academia and industry. Many factors are known to influence the expression yield in this organism e.g. the complementarity between the Shine-Dalgarno sequence (SD) and the 16S-rRNA or secondary structures in the translation initiation region of the transcript. In this study, we analysed the impact of the nucleotide composition between the SD sequence and the start codon (the spacer sequence) on the expression yield. We demonstrated that a polyadenylate-moiety spacer sequence moderately increases the expression level of laccase CotA from B. subtilis. By screening a library of artificially generated spacer variants, we identified clones with greatly increased expression levels of two model enzymes, the laccase CotA from B. subtilis (11 fold) and the metagenome derived protease H149 (30 fold). Furthermore, we demonstrated that the effect of the spacer sequence is specific to the gene of interest. These results prove the high impact of the spacer sequence on the expression yield in B. subtilis. © 2014 Elsevier B.V.