92 research outputs found
RosettaRemodel: A Generalized Framework for Flexible Backbone Protein Design
We describe RosettaRemodel, a generalized framework for flexible protein design that provides a versatile and convenient interface to the Rosetta modeling suite. RosettaRemodel employs a unified interface, called a blueprint, which allows detailed control over many aspects of flexible backbone protein design calculations. RosettaRemodel allows the construction and elaboration of customized protocols for a wide range of design problems ranging from loop insertion and deletion, disulfide engineering, domain assembly, loop remodeling, motif grafting, symmetrical units, to de novo structure modeling
<em>Enterococcus faecalis</em> Infection Causes Inflammation, Intracellular Oxphos-Independent ROS Production, and DNA Damage in Human Gastric Cancer Cells
Background: Achlorhydria caused by e.g. atrophic gastritis allows for bacterial overgrowth, which induces chronic inflammation and damage to the mucosal cells of infected individuals driving gastric malignancies and cancer. Enterococcus faecalis (E. faecalis) can colonize achlohydric stomachs and we therefore wanted to study the impact of E. faecalis infection on inflammatory response, reactive oxygen species (ROS) formation, mitochondrial respiration, and mitochondrial genetic stability in gastric mucosal cells. Methods: To separate the changes induced by bacteria from those of the inflammatory cells we established an in vitro E. faecalis infection model system using the gastric carcinoma cell line MKN74. Total ROS and superoxide was measured by fluorescence microscopy. Cellular oxygen consumption was characterized non-invasively using XF24 microplate based respirometry. Gene expression was examined by microarray, and response pathways were identified by Gene Set Analysis (GSA). Selected gene transcripts were verified by quantitative real-time polymerase chain reaction (qRT-PCR). Mitochondrial mutations were determined by sequencing. Results: Infection of MKN74 cells with E. faecalis induced intracellular ROS production through a pathway independent of oxidative phosphorylation (oxphos). Furthermore, E. faecalis infection induced mitochondrial DNA instability. Following infection, genes coding for inflammatory response proteins were transcriptionally up-regulated while DNA damage repair and cell cycle control genes were down-regulated. Cell growth slowed down when infected with viable E. faecalis and responded in a dose dependent manner to E. faecalis lysate. Conclusions: Infection by E. faecalis induced an oxphos-independent intracellular ROS response and damaged the mitochondrial genome in gastric cell culture. Finally the bacteria induced an NF-kappa B inflammatory response as well as impaired DNA damage response and cell cycle control gene expression
A Generic Program for Multistate Protein Design
Some protein design tasks cannot be modeled by the traditional single state design strategy of finding a sequence that is optimal for a single fixed backbone. Such cases require multistate design, where a single sequence is threaded onto multiple backbones (states) and evaluated for its strengths and weaknesses on each backbone. For example, to design a protein that can switch between two specific conformations, it is necessary to to find a sequence that is compatible with both backbone conformations. We present in this paper a generic implementation of multistate design that is suited for a wide range of protein design tasks and demonstrate in silico its capabilities at two design tasks: one of redesigning an obligate homodimer into an obligate heterodimer such that the new monomers would not homodimerize, and one of redesigning a promiscuous interface to bind to only a single partner and to no longer bind the rest of its partners. Both tasks contained negative design in that multistate design was asked to find sequences that would produce high energies for several of the states being modeled. Success at negative design was assessed by computationally redocking the undesired protein-pair interactions; we found that multistate design's accuracy improved as the diversity of conformations for the undesired protein-pair interactions increased. The paper concludes with a discussion of the pitfalls of negative design, which has proven considerably more challenging than positive design
The Gaia-ESO Public Spectroscopic Survey: Motivation, implementation, GIRAFFE data processing, analysis, and final data products
The Gaia-ESO Public Spectroscopic Survey is an ambitious project designed to
obtain astrophysical parameters and elemental abundances for 100,000 stars,
including large representative samples of the stellar populations in the
Galaxy, and a well-defined sample of 60 (plus 20 archive) open clusters. We
provide internally consistent results calibrated on benchmark stars and star
clusters, extending across a very wide range of abundances and ages. This
provides a legacy data set of intrinsic value, and equally a large wide-ranging
dataset that is of value for homogenisation of other and future stellar surveys
and Gaia's astrophysical parameters. This article provides an overview of the
survey methodology, the scientific aims, and the implementation, including a
description of the data processing for the GIRAFFE spectra. A companion paper
(arXiv:2206.02901) introduces the survey results. Gaia-ESO aspires to quantify
both random and systematic contributions to measurement uncertainties. Thus all
available spectroscopic analysis techniques are utilised, each spectrum being
analysed by up to several different analysis pipelines, with considerable
effort being made to homogenise and calibrate the resulting parameters. We
describe here the sequence of activities up to delivery of processed data
products to the ESO Science Archive Facility for open use. The Gaia-ESO Survey
obtained 202,000 spectra of 115,000 stars using 340 allocated VLT nights
between December 2011 and January 2018 from GIRAFFE and UVES. The full
consistently reduced final data set of spectra was released through the ESO
Science Archive Facility in late 2020, with the full astrophysical parameters
sets following in 2022
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