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Avidin cooperative allosterism upon binding biotin observed by differential changes in intrinsic fluorescence
Get PDFSimilar to streptavidin, the binding of biotin by avidin does not appear to be cooperative in the traditional sense of altered binding strength, though it appears to be cooperative in terms of ligand induced structural communication across subunits in the protein as previously shown for streptavidin. In this work we provide data from intrinsic tryptophan fluorescence as evidence of a cooperative structural change. The technique involves examination of the changes in fluorescence emission corresponding to the various tryptophan populations accompanying avidin-biotin binding. We note that the 335 nm emission population (i.e. more hydrophobic local environment) saturates prior to full ligation and the saturation of the 350 nm emission population commonly used in standard binding activity assays. We also note that total integrated fluorescence emission and peak height during the titration of ligand into streptavidin also reach saturation prior to the 4:1 stoichiometric end point. Unique to avidin and distinct from the behavior of streptavidin described in our prior work, the wavelength of maximum emission and full width at half maximum (FWHM) data do not saturate prior to the 4:1 stoichiometric end point. Avidin also exhibited larger FWHM for both apo and holo forms suggesting greater heterogeneity in local tryptophan environments, as compared to streptavidin. Taken together, the data suggests that the binding of the first 3 biotins effect greater structural changes in the protein than the final ligand in a similar way for avidin and streptavidin
Investigating the Role of NF-kB Inhibition on Müller Glia Proliferation Following Injury in the Zebrafish Retina
No full texthttps://collected.jcu.edu/celebration_2023/1005/thumbnail.jp
The Effect of S-glutahionylation of KEAP-1/NRF-2 and Caspase 3
Get PDFS-glutathionylation is a form of post-translational modification where glutathione forms disulfide bonds with protein cysteine residues under oxidative conditions. The process of Sglutathionylation is important because it is a reversible process, regulates enzyme activity, and may link to disease development. In this work, under physiological conditions, KEAP-1 and NRF-2 bind together as a complex. Upon oxidative stress, NRF-2 dissociates from KEAP-1 and triggers an antioxidant response. However, the dissociation mechanism was not well studied. S-glutathionylation of KEAP-1 causes dissociation of NRF-2. This result demonstrates a possible dissociation mechanism of NRF-2. Caspase 3 is a cysteine containing protein and a key enzyme in executing apoptosis in cells. The cysteine residue is required for its activity. Our results show that S-glutathionylation of the cysteine inhibits caspase 3 activity and that inhibition can be reversed by the addition of dithiothreitol (DTT). The inhibition of caspase 3 activity with GSSG and reactivation of caspase 3 activity with DTT showed a concentration dependent manner. Our work shows that the process of protein S-glutathionylation can affect cellular protein physiological functions under oxidative stress.https://collected.jcu.edu/celebration_2023/1004/thumbnail.jp
The Autism Symptom Dimensions Questionnaire: Development and psychometric evaluation of a new, open-source measure of autism symptomatology
Get PDFAim: To describe the development and initial psychometric evaluation of a new, freely available measure, the Autism Symptom Dimensions Questionnaire (ASDQ).
Method: After development and revision of an initial 33-item version, informants completed a revised 39-item version of the ASDQ on 1467 children and adolescents (aged 2-17 years), including 104 with autism spectrum disorder (ASD).
Results: The initial 33-item version of the ASDQ had good reliability and construct validity. However, only four specific symptom factors were identified, potentially due to an insufficient number of items. Factor analyses of the expanded instrument identified a general ASD factor and nine specific symptom factors with good measurement invariance across demographic groups. Scales showed good-to-excellent overall and conditional reliability. Exploratory analyses of predictive validity for ASD versus neurotypical and other developmental disability diagnoses indicated good accuracy for population and at-risk contexts.
Interpretation: The ASDQ is a free and psychometrically sound informant report instrument with good reliability of measurement across a continuous range of scores and preliminary evidence of predictive validity. The measure may be a useful alternative to existing autism symptom measures but further studies with comparison of clinical diagnoses using criterion-standard instruments are needed
A Selected Review of Exemplary Diversity Articles Published in the Journal of Management Education
Get PDFIssues related to diversity, equity, and inclusion (DEI) are timely topics in business, education, and politics. As Associate Editors for the Journal of Management Education (JME) we recognize the journal’s ability to contribute to these conversations. In this article, we take stock of DEI research in JME and review 17 exemplary articles published since 2000. A common theme in these articles is that management educators play an important role in creating inclusive classrooms to educate the next generation of leaders of multicultural organizations and that this task should be done proactively. Yet, even the most well-intentioned faculty members may be worried or lack the confidence to handle DEI-related challenges and conversations in the classroom. This collection of articles is intended to help guide business faculty through the unprecedented challenges associated with teaching DEI or having difficult discussions about diversity. The articles in this collection (1) advance the way we think about DEI by offering frameworks, reviews, and new perspectives, (2) address some of the most pressing and prevalent issues related to cultural-diversity and gender, and (3) provide activities and exercises to be implemented in the classroom to increase student sensitivity
WRITING FOR A “HIGH PURPOSE”: EXAMINING CHARLES CHESNUTT’S ANTIRACIST MANIPULATION OF GENRE AND LANGUAGE IN THE CONJURE WOMAN
Get PDFFeedback in Batesian mimetic systems
Get PDFWe propose a feedback model for Batesian mimetic trophic system dynamics that integrates evolutionary and ecological processes including those not directly related to mimicry such as nutrient transfer. The proposed feedback circuit includes a previously overlooked link, specifically: selection for predation on the mimetic phenotype, which results when predators consume palatable mimics, and which perpetuates predation on the mimetic phenotype that drives mimicry. Preservation of variation throughout the feedback loop may also explain polymorphism, suboptimal mimicry, and other aspects of mimetic trophic system evolution
Meta social technology and religion: a media ritual theory critical discourse
Get PDFThis paper explores the proposition that Meta social media and technology functions as a ritual platform and concludes affirmatively. It identifies and critically evaluates ritual elements on Meta’s platform. Employing media ritual theory in the context of religion, it analyzes the Meta for Faith homepage. Consequently, the investigation delves into Meta\u27s role in enhancing or diminishing the sacred rituals integral to religion, one of society\u27s oldest cultural institutions. The discussion expands by considering the implications of Meta for Faith offerings in religious rituals. Thus, this study contributes to the ongoing discourse on the increasing social technology mediatization in the rapidly evolving digital media landscape. It provides a novel perspective on the power dynamics of social media platforms within the framework of media communication ritual theory and religion