| 1. |
- Blom, Hans, et al.
(författare)
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STED microscopy : towards broadened use and scope of applications
- 2014
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Ingår i: Current opinion in chemical biology. - : Elsevier. - 1367-5931 .- 1879-0402. ; 20:1, s. 127-133
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Forskningsöversikt (refereegranskat)abstract
- High resolution Stimulated Emission Depletion (STED) microscopy has been demonstrated for fundamental studies in cells, living tissue and organisms. Today, a major trend in the STED technique development is to make the instruments simpler and more user-friendly, without compromising performance. This has become possible by new low-cost, turn-key laser technology and by implementing specifically designed phase plates and polarization elements, extending and simplifying the shaping of the laser beam profiles. These simpler and cheaper realizations of STED are now becoming more broadly available. In parallel with the continuous development of sample preparation and fluorophore reporter molecules ultimately setting the limit of the image quality, contrast and resolution, we can thus expect a significant increase in the use of STED, in science as well as for clinical and drug development purposes.
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| 2. |
- Buijs, Nicolaas, 1985, et al.
(författare)
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Advanced biofuel production by the yeast Saccharomyces cerevisiae
- 2013
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Ingår i: Current Opinion in Chemical Biology. - : Elsevier BV. - 1879-0402 .- 1367-5931. ; 17:3, s. 480-488
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Forskningsöversikt (refereegranskat)abstract
- Replacement of conventional transportation fuels with biofuels will require production of compounds that can cover the complete fuel spectrum, ranging from gasoline to kerosene. Advanced biofuels are expected to play an important role in replacing fossil fuels because they have improved properties compared with ethanol and some of these may have the energy density required for use in heavy duty vehicles, ships, and aviation. Moreover, advanced biofuels can be used as drop-in fuels in existing internal combustion engines. The yeast cell factory Saccharomyces cerevisiae can be turned into a producer of higher alcohols (1-butanol and isobutanol), sesquiterpenes (farnesene and bisabolene), and fatty acid ethyl esters (biodiesel), and here we discusses progress in metabolic engineering of S. cerevisiae for production of these advanced biofuels.
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| 3. |
- Fletcher, John, 1978, et al.
(författare)
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Label free biochemical 2D and 3D imaging using secondary ion mass spectrometry.
- 2011
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Ingår i: Current opinion in chemical biology. - : Elsevier BV. - 1879-0402 .- 1367-5931. ; 15:5, s. 733-40
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Forskningsöversikt (refereegranskat)abstract
- Time-of-flight secondary ion mass spectrometry (ToF-SIMS) provides a method for the detection of native and exogenous compounds in biological samples on a cellular scale. Through the development of novel ion beams the amount of molecular signal available from the sample surface has been increased. Through the introduction of polyatomic ion beams, particularly C(60), ToF-SIMS can now be used to monitor molecular signals as a function of depth as the sample is eroded thus proving the ability to generate 3D molecular images. Here we describe how this new capability has led to the development of novel instrumentation for 3D molecular imaging while also highlighting the importance of sample preparation and discuss the challenges that still need to be overcome to maximise the impact of the technique.
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| 4. |
- Hammer, Stephan C., et al.
(författare)
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Squalene hopene cyclases : highly promiscuous and evolvable catalysts for stereoselective CC and CX bond formation
- 2013
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Ingår i: Current opinion in chemical biology. - : Elsevier. - 1367-5931 .- 1879-0402. ; 17:2, s. 293-300
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Tidskriftsartikel (refereegranskat)abstract
- A review. We review here how the inherent promiscuous nature, as well as the evolvability of terpene cyclase enzymes enables new applications in chem. We mainly focus on squalene hopene cyclases, class II triterpene synthases that use a proton-initiated cationic polycyclization cascade to form carbopolycyclic products. We highlight recent findings to demonstrate that these enzymes are capable of activating different functionalities other than the traditional terminal isoprene CC-group as well as being compatible with a wide range of nucleophiles beyond the 'ene-functionality'. Thus, squalene hopene cyclases demonstrate a great potential to be used as a toolbox for general Bronsted acid catalysis.
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| 5. |
- Kohls, Hannes, et al.
(författare)
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Recent achievements in developing the biocatalytic toolbox for chiral amine synthesis
- 2014
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Ingår i: Current opinion in chemical biology. - : Elsevier BV. - 1367-5931 .- 1879-0402. ; 19, s. 180-192
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Tidskriftsartikel (refereegranskat)abstract
- Novel enzyme activities and chemoenzymatic reaction concepts have considerably expanded the biocatalytic toolbox for chiral amine synthesis. Creating new activities or extending the scope of existing enzymes by protein engineering is a common trend in biocatalysis and in chiral amine synthesis specifically. For instance, an amine dehydrogenase that allows for the direct asymmetric amination of ketones with ammonia was created by mutagenesis of an L-amino acid dehydrogenase. Another trend in chiral amine chemistry is the development of strategies allowing for the synthesis of secondary amines. For example the smart choice of substrates for amine transaminases provided access to secondary amines by chemoenzymatic reactions. Furthermore novel biocatalysts for the synthesis of secondary amines such as imine reductases and Pictet-Spenglerases have been identified and applied. Recent examples showed that the biocatalytic amine synthesis is emerging from simple model reactions towards industrial scale preparation of pharmaceutical relevant substances, for instance, as shown in the synthesis of a Janus kinase 2 inhibitor using an amine transaminase. A comparison of important process parameters such as turnover number and space-time yield demonstrates that biocatalytic strategies for asymmetric reductive amination are maturing and can already compete with established chemical methods.
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| 6. |
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| 7. |
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| 8. |
- Widersten, Mikael
(författare)
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Protein engineering for development of new hydrolytic biocatalysts
- 2014
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Ingår i: Current opinion in chemical biology. - : Elsevier BV. - 1367-5931 .- 1879-0402. ; 21, s. 42-47
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Forskningsöversikt (refereegranskat)abstract
- Hydrolytic enzymes play important roles as biocatalysts in chemical synthesis. The chemical versatility and structurally sturdy features of Candida antarctica lipase B has placed this enzyme as a common utensil in the synthetic tool-box. In addition to catalyzing acyl transfer reactions, a number of promiscuous activities have been described recently. Some of these new enzyme activities have been amplified by mutagenesis. Epoxide hydrolases are of interest due to their potential as catalysts in asymmetric synthesis. This current update discusses recent development in the engineering of lipases and epoxide hydrolases aiming to generate new biocatalysts with refined features as compared to the wild-type enzymes. Reported progress in improvements in reaction atom economy from dynamic kinetic resolution or enantioconvergence are also included.
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