| 1. |
- Sandquist, David, et al.
(författare)
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Microdistribution of xyloglucan in differentiating Poplar cells
- 2010
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Ingår i: Bioresources. - 1930-2126. ; 5, s. 796-807
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Tidskriftsartikel (refereegranskat)abstract
- Recent studies on the ultrastructure and composition of the gelatinous layer (g-layer) in poplar have reported findings of xyloglucan. Using correlated fluorescence, scanning- and transmission electron microscopy, we found evidence for xyloglucan present in and surrounding the g-layer, using the fucosylated xyloglucan specific CCRC-M1 antibody and the carbohydrate binding module FXG-14b. However, labeling of isolated gelatinous layer remained negative.
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| 2. |
- von Schantz, Laura, et al.
(författare)
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Affinity maturation generates greatly improved xyloglucan-specific carbohydrate binding modules
- 2009
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Ingår i: BMC Biotechnology. - : Springer Science and Business Media LLC. - 1472-6750. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- Background: Molecular evolution of carbohydrate binding modules (CBM) is a new approach for the generation of glycan-specific molecular probes. To date, the possibility of performing affinity maturation on CBM has not been investigated. In this study we show that binding characteristics such as affinity can be improved for CBM generated from the CBM4-2 scaffold by using random mutagenesis in combination with phage display technology. Results: Two modified proteins with greatly improved affinity for xyloglucan, a key polysaccharide abundant in the plant kingdom crucial for providing plant support, were generated. Both improved modules differ from other existing xyloglucan probes by binding to galactose-decorated subunits of xyloglucan. The usefulness of the evolved binders was verified by staining of plant sections, where they performed better than the xyloglucan-binding module from which they had been derived. They discriminated non-fucosylated from fucosylated xyloglucan as shown by their ability to stain only the endosperm, rich in non-fucosylated xyloglucan, but not the integument rich in fucosylated xyloglucan, on tamarind seed sections. Conclusion: We conclude that affinity maturation of CBM selected from molecular libraries based on the CBM4-2 scaffold is possible and has the potential to generate new analytical tools for detection of plant carbohydrates.
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| 3. |
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| 4. |
- Bazov, Igor, 1973-, et al.
(författare)
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Neuronal Expression of Opioid Gene is Controlled by Dual Epigenetic and Transcriptional Mechanism in Human Brain
- 2018
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Ingår i: Cerebral Cortex. - : Oxford University Press (OUP). - 1047-3211 .- 1460-2199. ; 28:9, s. 3129-3142
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Tidskriftsartikel (refereegranskat)abstract
- Molecular mechanisms that define patterns of neuropeptide expression are essential for the formation and rewiring of neural circuits. The prodynorphin gene (PDYN) gives rise to dynorphin opioid peptides mediating depression and substance dependence. We here demonstrated that PDYN is expressed in neurons in human dorsolateral prefrontal cortex (dlPFC), and identified neuronal differentially methylated region in PDYN locus framed by CCCTC-binding factor binding sites. A short, nucleosome size human-specific promoter CpG island (CGI), a core of this region may serve as a regulatory module, which is hypomethylated in neurons, enriched in 5-hydroxymethylcytosine, and targeted by USF2, a methylation-sensitive E-box transcription factor (TF). USF2 activates PDYN transcription in model systems, and binds to nonmethylated CGI in dlPFC. USF2 and PDYN expression is correlated, and USF2 and PDYN proteins are co-localized in dlPFC. Segregation of activatory TF and repressive CGI methylation may ensure contrasting PDYN expression in neurons and glia in human brain.
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| 5. |
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| 6. |
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| 7. |
- Daniel, Geoffrey, et al.
(författare)
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Chemical Pulping. The influence of xylan on the sensitivity towards fiber damage: Xylan added in the oxygen stage
- 2011
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The aim of this study was to investigate if extra xylan added during oxygen delignification of kraft spruce fibers could contribute to reduce the effect of fiber damage introduced during the cook. Two pulps were produced, one with and one without mechanical treatment at the end of the cook. The pulp produced without mechanical treatment was oxygen delignified with xylan added in the oxygen stage. The pulp produced with mechanical treatment was oxygen delignified both with and without xylan added. Results did not indicate that xylan added in the oxygen stage could repair the already introduced fiber damage. Added xylan had a fiber straightening effect as seen earlier when xylan was added in the cook. Xylan added in the oxygen stage resulted in improved tensile strength development. However, the negative effect from introduced mechanical treatment still influenced the strength properties more than could be compensated by the added xylan. SEM-images could not identify any differences between the investigated pulps. It seems likely that the birch xylan added forms a uniform but nonhomogeneous coating on the fiber surfaces. Possibly the xylan has penetrated into the fiber wall to a greater extent compared to previous studies when xylan was added in the cook
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| 8. |
- Daniel, Geoffrey, et al.
(författare)
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CRUW Chemical Pulping sub-project 1; The influence of xylan on the sensitivity towards fiber damage
- 2010
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The aim of this study was to determine if the presence and position of xylan in the fiber wall are of importance for the degree of damage introduced into fibers during mechanical action in the cook. Kraft pulps from spruce with different amounts of xylan have been produced in the laboratory, either by adding birch xylan in different positions in the cook or by redistribution of spruce xylan. At the end of the cook, fiber damages were introduced by subjecting the fibers to shear and compression forces. The extra birch xylan had adsorbed on the fiber surfaces, the outer fiber walls (presumably S1/primary wall) as well as on the fiber cell lumen wall. Xylan penetration into the fiber wall was very low. A large variation in coverage of surface xylan within the fibers and between fibers was noted. No significant difference between pulps produced in the different ways or between the pulps produced with or without mechanical treatment could however be observed. The extra xylan added resulted as expected in an improved tensile strength development for these pulps. No direct indications were seen that the extra xylan added during the cook resulted in a lower amount of introduced damaged areas. But some positive tendencies could be noted for the pulps produced with extra xylan added including: a lower kink/mm and lower amount of cleavage/fiber measured by the HCL method; and the zero-span level and tear-tensile relationship were not inferior compared to the reference despite the higher xylan content. The removal and subsequent re-introduction of xylan into the cook seemed to negatively influence the strength properties, i.e. the tear-tensile relationship was inferior compared to the reference pulp. The redistribution procedure may have drained the fiber wall of xylan negatively influencing the strength properties
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