Browse select publications produced by Icelabbers on this page by year or tag using the filters below, or type in an author name to search for publications by that author.
*For full and completely up to date publications visit individual researchers’ profiles on their own websites or in publication collectors like Google Scholar, ResearchGate, PubMed, etc.
Strand, Tamara Hernández-Verdeja; Linda Vuorijoki; Xu Jin; Alexander Vergara; Carole Dubreuil; Åsa GENOMES UNCOUPLED1 plays a key role during the de-etiolation process in Arabidopsis Journal Article In: New Phytologist, vol. 235, iss. 1, pp. 188-203, 2022. Malyshev, Dmitry; Öberg, Rasmus; Landström, Lars; Andersson, Per Ola; Dahlberg, Tobias; Andersson, Magnus pH-induced changes in Raman, UV–vis absorbance, and fluorescence spectra of dipicolinic acid (DPA) Journal Article In: Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, vol. 271, pp. 120869, 2022, ISSN: 13861425. Cohn, Alexa R; Orsi, Renato H; Carroll, Laura M; Liao, Jingqiu; Wiedmann, Martin; Cheng, Rachel A Salmonella enterica serovar Cerro displays a phylogenetic structure and genomic features consistent with virulence attenuation and adaptation to cattle Journal Article In: Frontiers in Microbiology, vol. 13, pp. 4725, 2022. BibTeX | Tags: Gaballa, Ahmed; Wiedmann, Martin; Carroll, Laura M More than mcr: Canonical Plasmid-and Transposon-Encoded Mobilized Colistin Resistance (mcr) Genes Represent a Subset of Phosphoethanolamine Transferases Journal Article In: bioRxiv, 2022. BibTeX | Tags: Carroll, Laura M; Matle, Itumeleng; Kovac, Jasna; Cheng, Rachel A; Wiedmann, Martin Laboratory Misidentifications Resulting from Taxonomic Changes to Bacillus cereus Group Species, 2018--2022 Journal Article In: Europe, 2022. BibTeX | Tags: Carroll, Laura M; Marston, Chung K; Kolton, Cari B; Gulvik, Christopher A; Gee, Jay E; Weiner, Zachary P; Kovac, Jasna Strains Associated with Two 2020 Welder Anthrax Cases in the United States Belong to Separate Lineages within Bacillus cereus sensu lato Journal Article In: Pathogens, vol. 11, no. 8, pp. 856, 2022. BibTeX | Tags: Paoli, Lucas; Ruscheweyh, Hans-Joachim; Forneris, Clarissa C; Hubrich, Florian; Kautsar, Satria; Bhushan, Agneya; Lotti, Alessandro; Clayssen, Quentin; Salazar, Guillem; Milanese, Alessio; others, Biosynthetic potential of the global ocean microbiome Journal Article In: Nature, vol. 607, no. 7917, pp. 111–118, 2022. BibTeX | Tags: Carroll, Laura M; Pierneef, Rian; Mathole, Aletta; Atanda, Abimbola; Matle, Itumeleng Genomic Sequencing of Bacillus cereus Sensu Lato Strains Isolated from Meat and Poultry Products in South Africa Enables Inter-and Intranational Surveillance and Source Tracking Journal Article In: Microbiology Spectrum, pp. e00700–22, 2022. BibTeX | Tags: Carroll, Laura M; Piacenza, Nicolo; Cheng, Rachel A; Wiedmann, Martin; Guldimann, Claudia A multidrug-resistant Salmonella enterica serotype Typhimurium DT104 lineage circulating among humans and cattle in the United States lost the ability to produce pertussis-like toxin ArtAB in close temporal proximity to the global DT104 epidemic Journal Article In: bioRxiv, 2022. BibTeX | Tags: Mahoney, David Burke James; Falardeau, Justin; Hingston, Patricia; Chmielowska, Cora; Carroll, Laura M; Wiedmann, Martin; Jang, Sung Sik; Wang, Siyun Associations between Listeria monocytogenes genomic characteristics and adhesion to polystyrene at 8° C Journal Article In: Food Microbiology, vol. 102, pp. 103915, 2022. BibTeX | Tags: Carroll, Laura M; Cheng, Rachel A; Wiedmann, Martin; Kovac, Jasna Keeping up with the Bacillus cereus group: taxonomy through the genomics era and beyond Journal Article In: Critical reviews in food science and nutrition, vol. 62, no. 28, pp. 7677–7702, 2022. BibTeX | Tags: Solowiej-Wedderburn, Josephine; Dunlop, Carina M. Cell strain energy costs of active control of contractility Journal Article In: bioRxiv, 2022. Abstract | Links | BibTeX | Tags: Solowiej-Wedderburn, Josephine; Dunlop, Carina Sticking around: Cell adhesion patterning for energy minimization and substrate mechanosensing Journal Article In: Biophysical Journal, vol. 121, 2022. Malyshev, Dmitry; Öberg, Rasmus; Dahlberg, Tobias; Wiklund, Krister; Landström, Lars; Andersson, Per Ola; Andersson, Magnus Laser induced degradation of bacterial spores during micro-Raman spectroscopy Journal Article In: Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, vol. 265, pp. 120381, 2022, ISSN: 13861425. Vergara, Alexander; Haas, Julia Christa; Aro, Tuuli; Stachula, Paulina; Street, Nathaniel Robert; Hurry, Vaughan Norway spruce deploys tissue-specific responses during acclimation to cold Journal Article In: Plant Cell and Environment, 2021, ISSN: 13653040. Abstract | Links | BibTeX | Tags: cold, Norway spruce, transcriptome Christie, Nanette; Mannapperuma, Chanaka; Ployet, Raphael; Merwe, Karen; Mähler, Niklas; Delhomme, Nicolas; Naidoo, Sanushka; Mizrachi, Eshchar; Street, Nathaniel R.; Myburg, Alexander A. qtlXplorer: an online systems genetics browser in the Eucalyptus Genome Integrative Explorer (EucGenIE) Journal Article In: BMC Bioinformatics 2021 22:1, vol. 22, no. 1, pp. 1–21, 2021, ISSN: 1471-2105. Abstract | Links | BibTeX | Tags: Algorithms, Bioinformatics, Computational Biology/Bioinformatics, Computer Appl. in Life Sciences, Microarrays Panadeiro, Veronica; Rodriguez, Alvaro; Henry, Jason; Wlodkowic, Donald; Andersson, Magnus A review of 28 free animal-tracking software applications: current features and limitations Journal Article In: Lab Animal, vol. 50, no. 9, pp. 246–254, 2021, ISSN: 0093-7355. Abstract | Links | BibTeX | Tags: Näsström, Thomas; Dahlberg, Tobias; Malyshev, Dmitry; Ådén, Jörgen; Andersson, Per Ola; Andersson, Magnus; Karlsson, Björn C G Synthetic NAC 71-82 Peptides Designed to Produce Fibrils with Different Protofilament Interface Contacts Journal Article In: International Journal of Molecular Sciences, vol. 22, no. 17, pp. 9334, 2021, ISSN: 1422-0067. Abstract | Links | BibTeX | Tags: $alpha$ -synuclein, fibril polymorphs, nac 71-82 peptides Dahlberg, Tobias; Andersson, Magnus Optical design for laser tweezers Raman spectroscopy setups for increased sensitivity and flexible spatial detection Journal Article In: Applied Optics, vol. 60, no. 16, pp. 4519, 2021, ISSN: 1559-128X. Abstract | Links | BibTeX | Tags: Baker, Joseph L; Dahlberg, Tobias; Bullitt, Esther; Andersson, Magnus Impact of an alpha helix and a cysteine–cysteine disulfide bond on the resistance of bacterial adhesion pili to stress Journal Article In: Proceedings of the National Academy of Sciences, vol. 118, no. 21, pp. e2023595118, 2021, ISSN: 0027-8424. Abstract | Links | BibTeX | Tags: @article{Hernández-Verdeja2022,
title = {GENOMES UNCOUPLED1 plays a key role during the de-etiolation process in Arabidopsis},
author = {Tamara Hernández-Verdeja; Linda Vuorijoki; Xu Jin; Alexander Vergara; Carole Dubreuil; Åsa Strand},
doi = {https://doi.org/10.1111/nph.18115},
year = {2022},
date = {2022-07-01},
urldate = {2022-07-01},
journal = {New Phytologist},
volume = {235},
issue = {1},
pages = {188-203},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
@article{Malyshev2022a,
title = {pH-induced changes in Raman, UV–vis absorbance, and fluorescence spectra of dipicolinic acid (DPA)},
author = {Dmitry Malyshev and Rasmus Öberg and Lars Landström and Per Ola Andersson and Tobias Dahlberg and Magnus Andersson},
url = {https://linkinghub.elsevier.com/retrieve/pii/S1386142522000178},
doi = {10.1016/j.saa.2022.120869},
issn = {13861425},
year = {2022},
date = {2022-04-01},
journal = {Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy},
volume = {271},
pages = {120869},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
@article{cohn2022salmonella,
title = {Salmonella enterica serovar Cerro displays a phylogenetic structure and genomic features consistent with virulence attenuation and adaptation to cattle},
author = {Alexa R Cohn and Renato H Orsi and Laura M Carroll and Jingqiu Liao and Martin Wiedmann and Rachel A Cheng},
year = {2022},
date = {2022-01-01},
journal = {Frontiers in Microbiology},
volume = {13},
pages = {4725},
publisher = {Frontiers},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
@article{gaballa2022more,
title = {More than mcr: Canonical Plasmid-and Transposon-Encoded Mobilized Colistin Resistance (mcr) Genes Represent a Subset of Phosphoethanolamine Transferases},
author = {Ahmed Gaballa and Martin Wiedmann and Laura M Carroll},
year = {2022},
date = {2022-01-01},
journal = {bioRxiv},
publisher = {Cold Spring Harbor Laboratory},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
@article{carroll2022laboratory,
title = {Laboratory Misidentifications Resulting from Taxonomic Changes to Bacillus cereus Group Species, 2018--2022},
author = {Laura M Carroll and Itumeleng Matle and Jasna Kovac and Rachel A Cheng and Martin Wiedmann},
year = {2022},
date = {2022-01-01},
journal = {Europe},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
@article{carroll2022strains,
title = {Strains Associated with Two 2020 Welder Anthrax Cases in the United States Belong to Separate Lineages within Bacillus cereus sensu lato},
author = {Laura M Carroll and Chung K Marston and Cari B Kolton and Christopher A Gulvik and Jay E Gee and Zachary P Weiner and Jasna Kovac},
year = {2022},
date = {2022-01-01},
journal = {Pathogens},
volume = {11},
number = {8},
pages = {856},
publisher = {MDPI},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
@article{paoli2022biosynthetic,
title = {Biosynthetic potential of the global ocean microbiome},
author = {Lucas Paoli and Hans-Joachim Ruscheweyh and Clarissa C Forneris and Florian Hubrich and Satria Kautsar and Agneya Bhushan and Alessandro Lotti and Quentin Clayssen and Guillem Salazar and Alessio Milanese and others},
year = {2022},
date = {2022-01-01},
journal = {Nature},
volume = {607},
number = {7917},
pages = {111--118},
publisher = {Nature Publishing Group},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
@article{carroll2022genomic,
title = {Genomic Sequencing of Bacillus cereus Sensu Lato Strains Isolated from Meat and Poultry Products in South Africa Enables Inter-and Intranational Surveillance and Source Tracking},
author = {Laura M Carroll and Rian Pierneef and Aletta Mathole and Abimbola Atanda and Itumeleng Matle},
year = {2022},
date = {2022-01-01},
journal = {Microbiology Spectrum},
pages = {e00700--22},
publisher = {American Society for Microbiology 1752 N St., NW, Washington, DC},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
@article{carroll2022multidrug,
title = {A multidrug-resistant Salmonella enterica serotype Typhimurium DT104 lineage circulating among humans and cattle in the United States lost the ability to produce pertussis-like toxin ArtAB in close temporal proximity to the global DT104 epidemic},
author = {Laura M Carroll and Nicolo Piacenza and Rachel A Cheng and Martin Wiedmann and Claudia Guldimann},
year = {2022},
date = {2022-01-01},
journal = {bioRxiv},
publisher = {Cold Spring Harbor Laboratory},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
@article{mahoney2022associations,
title = {Associations between Listeria monocytogenes genomic characteristics and adhesion to polystyrene at 8° C},
author = {David Burke James Mahoney and Justin Falardeau and Patricia Hingston and Cora Chmielowska and Laura M Carroll and Martin Wiedmann and Sung Sik Jang and Siyun Wang},
year = {2022},
date = {2022-01-01},
journal = {Food Microbiology},
volume = {102},
pages = {103915},
publisher = {Academic Press},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
@article{carroll2022keeping,
title = {Keeping up with the Bacillus cereus group: taxonomy through the genomics era and beyond},
author = {Laura M Carroll and Rachel A Cheng and Martin Wiedmann and Jasna Kovac},
year = {2022},
date = {2022-01-01},
journal = {Critical reviews in food science and nutrition},
volume = {62},
number = {28},
pages = {7677--7702},
publisher = {Taylor & Francis},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
@article{Solowiej-Wedderburn2022.09.16.508225,
title = {Cell strain energy costs of active control of contractility},
author = {Josephine Solowiej-Wedderburn and Carina M. Dunlop},
url = {https://www.biorxiv.org/content/early/2022/09/16/2022.09.16.508225},
doi = {10.1101/2022.09.16.508225},
year = {2022},
date = {2022-01-01},
journal = {bioRxiv},
publisher = {Cold Spring Harbor Laboratory},
abstract = {Cell mechanosensing is implicated in the control of a broad range of cell behaviours, with cytoskeletal contractility a key component. Experimentally, it is observed that the contractility of the cell responds to increasing substrate stiffness, showing increased contractile force and changing the distribution of cytoskeletal elements. Here we show using a theoretical model of active cell contractility that upregulation of contractility need not be energetically expensive, especially when combined with changes in adhesion and contractile distribution. Indeed, we show that a feedback mechanism based on maintenance of strain energy would require an upregulation in contractile pressure on all but the softest substrates. We consider both the commonly reported substrate strain energy and active work done. We demonstrate substrate strain energy would select for the observed clustering of cell adhesions on stiffer substrates which also enable an upregulation of total contractile pressure; while localisation of contractility has the greatest impact on the internal work.Competing Interest StatementThe authors have declared no competing interest.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
@article{articlej,
title = {Sticking around: Cell adhesion patterning for energy minimization and substrate mechanosensing},
author = {Josephine Solowiej-Wedderburn and Carina Dunlop},
doi = {10.1016/j.bpj.2022.03.017},
year = {2022},
date = {2022-01-01},
journal = {Biophysical Journal},
volume = {121},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
@article{Malyshev2022,
title = {Laser induced degradation of bacterial spores during micro-Raman spectroscopy},
author = {Dmitry Malyshev and Rasmus Öberg and Tobias Dahlberg and Krister Wiklund and Lars Landström and Per Ola Andersson and Magnus Andersson},
url = {https://doi.org/10.1016/j.saa.2021.120381 https://linkinghub.elsevier.com/retrieve/pii/S1386142521009586},
doi = {10.1016/j.saa.2021.120381},
issn = {13861425},
year = {2022},
date = {2022-01-01},
journal = {Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy},
volume = {265},
pages = {120381},
publisher = {The Author(s)},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
@article{Vergara2021,
title = {Norway spruce deploys tissue-specific responses during acclimation to cold},
author = {Alexander Vergara and Julia Christa Haas and Tuuli Aro and Paulina Stachula and Nathaniel Robert Street and Vaughan Hurry},
url = {https://onlinelibrary.wiley.com/doi/full/10.1111/pce.14241 https://onlinelibrary.wiley.com/doi/abs/10.1111/pce.14241 https://onlinelibrary.wiley.com/doi/10.1111/pce.14241},
doi = {10.1111/pce.14241},
issn = {13653040},
year = {2021},
date = {2021-12-01},
journal = {Plant Cell and Environment},
publisher = {John Wiley & Sons, Ltd},
abstract = {Climate change in the conifer-dominated boreal forest is expected to lead to warmer but more dynamic winter air temperatures, reducing the depth and duration of snow cover and lowering winter soil temperatures. To gain insight into the mechanisms that have enabled conifers to dominate extreme cold environments, we performed genome-wide RNA-Seq analysis from needles and roots of non-dormant two-year Norway spruce (Picea abies (L.) H. Karst), and contrasted these response to herbaceous model Arabidopsis We show that the main transcriptional response of Norway spruce needles exposed to cold was delayed relative to Arabidopsis, and this delay was associated with slower development of freezing tolerance. Despite this difference in timing, Norway spruce principally utilizes early response transcription factors (TFs) belonging to the same gene families as Arabidopsis, indicating broad evolutionary conservation of cold response networks. In keeping with their different metabolic and developmental states, needles and root of Norway spruce showed contrasting results. Regulatory network analysis identified both conserved TFs with known roles in cold acclimation (e.g. homologs of ICE1, AKS3, and of the NAC and AP2/ERF superfamilies), but also a root-specific bHLH101 homolog, providing functional insights into cold stress response strategies in Norway spruce.},
keywords = {cold, Norway spruce, transcriptome},
pubstate = {published},
tppubtype = {article}
}
@article{Christie2021,
title = {qtlXplorer: an online systems genetics browser in the Eucalyptus Genome Integrative Explorer (EucGenIE)},
author = {Nanette Christie and Chanaka Mannapperuma and Raphael Ployet and Karen Merwe and Niklas Mähler and Nicolas Delhomme and Sanushka Naidoo and Eshchar Mizrachi and Nathaniel R. Street and Alexander A. Myburg},
url = {https://bmcbioinformatics.biomedcentral.com/articles/10.1186/s12859-021-04514-9},
doi = {10.1186/S12859-021-04514-9},
issn = {1471-2105},
year = {2021},
date = {2021-12-01},
journal = {BMC Bioinformatics 2021 22:1},
volume = {22},
number = {1},
pages = {1--21},
publisher = {BioMed Central},
abstract = {Affordable high-throughput DNA and RNA sequencing technologies are allowing genomic analysis of plant and animal populations and as a result empowering new systems genetics approaches to study complex traits. The availability of intuitive tools to browse and analyze the resulting large-scale genetic and genomic datasets remain a significant challenge. Furthermore, these integrative genomics approaches require innovative methods to dissect the flow and interconnectedness of biological information underlying complex trait variation. The Plant Genome Integrative Explorer (PlantGenIE.org) is a multi-species database and domain that houses online tools for model and woody plant species including Eucalyptus. Since the Eucalyptus Genome Integrative Explorer (EucGenIE) is integrated within PlantGenIE, it shares genome and expression analysis tools previously implemented within the various subdomains (ConGenIE, PopGenIE and AtGenIE). Despite the success in setting up integrative genomics databases, online tools for systems genetics modelling and high-resolution dissection of complex trait variation in plant populations have been lacking. We have developed qtlXplorer (
https://eucgenie.org/QTLXplorer
) for visualizing and exploring systems genetics data from genome-wide association studies including quantitative trait loci (QTLs) and expression-based QTL (eQTL) associations. This module allows users to, for example, find co-located QTLs and eQTLs using an interactive version of Circos, or explore underlying genes using JBrowse. It provides users with a means to build systems genetics models and generate hypotheses from large-scale population genomics data. We also substantially upgraded the EucGenIE resource and show how it enables users to combine genomics and systems genetics approaches to discover candidate genes involved in biotic stress responses and wood formation by focusing on two multigene families, laccases and peroxidases. qtlXplorer adds a new dimension, population genomics, to the EucGenIE and PlantGenIE environment. The resource will be of interest to researchers and molecular breeders working in Eucalyptus and other woody plant species. It provides an example of how systems genetics data can be integrated with functional genetics data to provide biological insight and formulate hypotheses. Importantly, integration within PlantGenIE enables novel comparative genomics analyses to be performed from population-scale data.},
keywords = {Algorithms, Bioinformatics, Computational Biology/Bioinformatics, Computer Appl. in Life Sciences, Microarrays},
pubstate = {published},
tppubtype = {article}
}
https://eucgenie.org/QTLXplorer
) for visualizing and exploring systems genetics data from genome-wide association studies including quantitative trait loci (QTLs) and expression-based QTL (eQTL) associations. This module allows users to, for example, find co-located QTLs and eQTLs using an interactive version of Circos, or explore underlying genes using JBrowse. It provides users with a means to build systems genetics models and generate hypotheses from large-scale population genomics data. We also substantially upgraded the EucGenIE resource and show how it enables users to combine genomics and systems genetics approaches to discover candidate genes involved in biotic stress responses and wood formation by focusing on two multigene families, laccases and peroxidases. qtlXplorer adds a new dimension, population genomics, to the EucGenIE and PlantGenIE environment. The resource will be of interest to researchers and molecular breeders working in Eucalyptus and other woody plant species. It provides an example of how systems genetics data can be integrated with functional genetics data to provide biological insight and formulate hypotheses. Importantly, integration within PlantGenIE enables novel comparative genomics analyses to be performed from population-scale data.@article{Panadeiro2021,
title = {A review of 28 free animal-tracking software applications: current features and limitations},
author = {Veronica Panadeiro and Alvaro Rodriguez and Jason Henry and Donald Wlodkowic and Magnus Andersson},
url = {http://dx.doi.org/10.1038/s41684-021-00811-1 https://www.nature.com/articles/s41684-021-00811-1},
doi = {10.1038/s41684-021-00811-1},
issn = {0093-7355},
year = {2021},
date = {2021-09-01},
journal = {Lab Animal},
volume = {50},
number = {9},
pages = {246--254},
publisher = {Springer US},
abstract = {Well-quantified laboratory studies can provide a fundamental understanding of animal behavior in ecology, ethology and ecotoxicology research. These types of studies require observation and tracking of each animal in well-controlled and defined arenas, often for long timescales. Thus, these experiments produce long time series and a vast amount of data that require the use of software applications to automate the analysis and reduce manual annotation. In this review, we examine 28 free software applications for animal tracking to guide researchers in selecting the software that might best suit a particular experiment. We also review the algorithms in the tracking pipeline of the applications, explain how specific techniques can fit different experiments, and finally, expose each approach's weaknesses and strengths. Our in-depth review includes last update, type of platform, user-friendliness, off- or online video acquisition, calibration method, background subtraction and segmentation method, species, multiple arenas, multiple animals, identity preservation, manual identity correction, data analysis and extra features. We found, for example, that out of 28 programs, only 3 include a calibration algorithm to reduce image distortion and perspective problems that affect accuracy and can result in substantial errors when analyzing trajectories and extracting mobility or explored distance. In addition, only 4 programs can directly export in-depth tracking and analysis metrics, only 5 are suited for tracking multiple unmarked animals for more than a few seconds and only 11 have been updated in the period 2019–2021.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
@article{Nasstrom2021,
title = {Synthetic NAC 71-82 Peptides Designed to Produce Fibrils with Different Protofilament Interface Contacts},
author = {Thomas Näsström and Tobias Dahlberg and Dmitry Malyshev and Jörgen Ådén and Per Ola Andersson and Magnus Andersson and Björn C G Karlsson},
url = {https://www.mdpi.com/1422-0067/22/17/9334},
doi = {10.3390/ijms22179334},
issn = {1422-0067},
year = {2021},
date = {2021-08-01},
journal = {International Journal of Molecular Sciences},
volume = {22},
number = {17},
pages = {9334},
abstract = {Alpha-synucleinopathies are featured by fibrillar inclusions in brain cells. Although $alpha$-synuclein fibrils display structural diversity, the origin of this diversity is not fully understood. We used molecular dynamics simulations to design synthetic peptides, based on the NAC 71-82 amino acid fragment of $alpha$-synuclein, that govern protofilament contacts and generation of twisted fibrillar polymorphs. Four peptides with structures based on either single or double fragments and capped or non-capped ends were selected for further analysis. We determined the fibrillar yield and the structures from these peptides found in the solution after fibrillisation using protein concentration determination assay and circular dichroism spectroscopy. In addition, we characterised secondary structures formed by individual fibrillar complexes using laser-tweezers Raman spectroscopy. Results suggest less mature fibrils, based on the lower relative $beta$-sheet content for double- than single-fragment peptide fibrils. We confirmed this structural difference by TEM analysis which revealed, in addition to short protofibrils, more elongated, twisted and rod-like fibril structures in non-capped and capped double-fragment peptide systems, respectively. Finally, time-correlated single-photon counting demonstrated a difference in the Thioflavin T fluorescence lifetime profiles upon fibril binding. It could be proposed that this difference originated from morphological differences in the fibril samples. Altogether, these results highlight the potential of using peptide models for the generation of fibrils that share morphological features relevant for disease, e.g., twisted and rod-like polymorphs.},
keywords = {$alpha$ -synuclein, fibril polymorphs, nac 71-82 peptides},
pubstate = {published},
tppubtype = {article}
}
@article{Dahlberg2021,
title = {Optical design for laser tweezers Raman spectroscopy setups for increased sensitivity and flexible spatial detection},
author = {Tobias Dahlberg and Magnus Andersson},
url = {https://www.osapublishing.org/abstract.cfm?URI=ao-60-16-4519},
doi = {10.1364/AO.424595},
issn = {1559-128X},
year = {2021},
date = {2021-06-01},
journal = {Applied Optics},
volume = {60},
number = {16},
pages = {4519},
abstract = {We demonstrate a method to double the collection efficiency in Laser Tweezers Raman Spectroscopy (LTRS) by collecting both the forward and back-scattered light in a single-shot multitrack measurement. Our method can collect signals at different sample volumes, granting both the pinpoint spatial selectivity of confocal Raman and the bulk sensitivity of non-confocal Raman simultaneously. Further, we display that our approach allows for reduced detector integration time and laser power. Thus, our method will enable the monitoring of biological samples sensitive to high intensities for longer times. Additionally, we demonstrate that by a simple modification, we can add polarization sensitivity and retrieve extra biochemical information.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
@article{Baker2021,
title = {Impact of an alpha helix and a cysteine–cysteine disulfide bond on the resistance of bacterial adhesion pili to stress},
author = {Joseph L Baker and Tobias Dahlberg and Esther Bullitt and Magnus Andersson},
url = {http://biorxiv.org/content/early/2021/01/19/2021.01.18.427124.abstract http://www.pnas.org/lookup/doi/10.1073/pnas.2023595118},
doi = {10.1073/pnas.2023595118},
issn = {0027-8424},
year = {2021},
date = {2021-05-01},
journal = {Proceedings of the National Academy of Sciences},
volume = {118},
number = {21},
pages = {e2023595118},
abstract = {Escherichia coli express adhesion pili that mediate attachment to host cell surfaces and are exposed to body fluids in the urinary and gastrointestinal tracts. Pilin subunits are organized into helical polymers, with a tip adhesin for specific host binding. Pili can elastically unwind when exposed to fluid flow forces, reducing the adhesin load, thereby facilitating sustained attachment. Here we investigate biophysical and structural differences of pili commonly expressed on bacteria that inhabit the urinary and intestinal tracts. Optical tweezers measurements reveal that class 1a pili of uropathogenic E. coli (UPEC), as well as class 1b of enterotoxigenic E. coli (ETEC), undergo an additional conformational change beyond pilus unwinding, providing significantly more elasticity to their structure than ETEC class 5 pili. Examining structural and steered molecular dynamics simulation data, we find that this difference in class 1 pili subunit behavior originates from an $alpha$-helical motif that can unfold when exposed to force. A disulfide bond cross-linking $beta$-strands in class 1 pili stabilizes subunits, allowing them to tolerate higher forces than class 5 pili that lack this covalent bond. We suggest that these extra contributions to pilus resiliency are relevant for the UPEC niche, since resident bacteria are exposed to stronger, more transient drag forces compared to those experienced by ETEC bacteria in the mucosa of the intestinal tract. Interestingly, class 1b ETEC pili include the same structural features seen in UPEC pili, while requiring lower unwinding forces that are more similar to those of class 5 ETEC pili.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}