Perspectives of socioeconomically disadvantaged parents on their children's coping during COVID-19: Implications for practice

Disruptions caused by COVID-19 have the potential to create long-term negative impacts on children's well-being and development, especially among socioeconomically disadvantaged children. However, we know little about how socioeconomically disadvantaged families are coping with the pandemic, nor the types of support needed. This study presents qualitative analysis of responses to an open-ended question asking parents how children are coping with the restrictions associated with COVID-19, to identify areas in which these cohorts can be supported. Four main themes were identified: health concerns, schooling difficulties, social isolation and adjustment to restrictions. Health concerns included exacerbation of pre-existing health conditions, fear about the virus, difficulty getting children to understand the pandemic and increased sedentary behaviour. Schooling difficulties referred to the challenges of home schooling, which were behavioural (e.g. difficulty concentrating) and logistical (e.g. technology). Social isolation, expressed as missing friends, family and/or institutions was common. Finally, parents expressed that children experienced both positive adjustments to restrictions, such as spending more time with family, and negative adjustments such as increased screen time. Many responses from parents touched on topics across multiple themes, indicating a need for comprehensive, holistic assessment of children's and families' needs in the provision of support services. The content of the themes supports calls for resources to support children and families including increased financial and practical accessibility of social services, physical health and exercise support, mental health support and COVID-19 communication guides

The evolution of multiple active site configurations in a designed enzyme

Developments in computational chemistry, bioinformatics, and laboratory evolution have facilitated the de novo design and catalytic optimization of enzymes. Besides creating useful catalysts, the generation and iterative improvement of designed enzymes can provide valuable insight into the interplay between the many phenomena that have been suggested to contribute to catalysis. In this work, we follow changes in conformational sampling, electrostatic preorganization, and quantum tunneling along the evolutionary trajectory of a designed Kemp eliminase. We observe that in the Kemp Eliminase KE07, instability of the designed active site leads to the emergence of two additional active site configurations. Evolutionary conformational selection then gradually stabilizes the most efficient configuration, leading to an improved enzyme. This work exemplifies the link between conformational plasticity and evolvability and demonstrates that residues remote from the active sites of enzymes play crucial roles in controlling and shaping the active site for efficient catalysis

Interaction of short modified peptides deriving from glycoprotein gp36 of feline immunodeficiency virus with phospholipid membranes

A tryptophan-rich octapeptide, C8 (Ac-Trp-Glu-Asp-Trp-Val-Gly-Trp-Ile-NH2), modelled on the membrane-proximal external region of the feline immunodeficiency virus (FIV) gp36 glycoprotein ectodomain, exhibits potent antiviral activity against FIV. A mechanism has been proposed by which the peptide, being positioned on the surface of the cell membrane, inhibits its fusion with the virus. In the present work, peptide–lipid interactions of C8 with dimyristoyl phosphatidylcholine liposomes are investigated using electron spin resonance spectroscopy of spin-labelled lipids. Three other peptides, obtained from modifications of C8, have also been investigated, in an attempt to clarify the essential molecular features of the interactions involving the tryptophan residues. The results show that C8 adsorbs strongly on the bilayer surface. Membrane binding requires not only the presence of the Trp residues in the sequence, but also their common orientation on one side of the peptide that is engendered by the WX2 WX2 W motif. Membrane interaction correlates closely with peptide antiviral activity, indicating that the membrane is essential in stabilizing the peptide conformation that will be able to inhibit viral infection

Long-Distance Translocation of Protein during Morphogenesis of the Fruiting Body in the Filamentous Fungus, Agaricus bisporus

Commercial cultivation of the mushroom fungus, Agaricus bisporus, utilizes a substrate consisting of a lower layer of compost and upper layer of peat. Typically, the two layers are seeded with individual mycelial inoculants representing a single genotype of A. bisporus. Studies aimed at examining the potential of this fungal species as a heterologous protein expression system have revealed unexpected contributions of the mycelial inoculants in the morphogenesis of the fruiting body. These contributions were elucidated using a dual-inoculant method whereby the two layers were differientially inoculated with transgenic β-glucuronidase (GUS) and wild-type (WT) lines. Surprisingly, use of a transgenic GUS line in the lower substrate and a WT line in the upper substrate yielded fruiting bodies expressing GUS activity while lacking the GUS transgene. Results of PCR and RT-PCR analyses for the GUS transgene and RNA transcript, respectively, suggested translocation of the GUS protein from the transgenic mycelium colonizing the lower layer into the fruiting body that developed exclusively from WT mycelium colonizing the upper layer. Effective translocation of the GUS protein depended on the use of a transgenic line in the lower layer in which the GUS gene was controlled by a vegetative mycelium-active promoter (laccase 2 and β-actin), rather than a fruiting body-active promoter (hydrophobin A). GUS-expressing fruiting bodies lacking the GUS gene had a bonafide WT genotype, confirmed by the absence of stably inherited GUS and hygromycin phosphotransferase selectable marker activities in their derived basidiospores and mycelial tissue cultures. Differientially inoculating the two substrate layers with individual lines carrying the GUS gene controlled by different tissue-preferred promoters resulted in up to a ∼3.5-fold increase in GUS activity over that obtained with a single inoculant. Our findings support the existence of a previously undescribed phenomenon of long-distance protein translocation in A. bisporus that has potential application in recombinant protein expression and biotechnological approaches for crop improvement

Perspectives of socioeconomically disadvantaged parents on their children's coping during COVID-19: Implications for practice

Disruptions caused by COVID-19 have the potential to create long-term negative impacts on children's well-being and development, especially among socioeconomically disadvantaged children. However, we know little about how socioeconomically disadvantaged families are coping with the pandemic, nor the types of support needed. This study presents qualitative analysis of responses to an open-ended question asking parents how children are coping with the restrictions associated with COVID-19, to identify areas in which these cohorts can be supported. Four main themes were identified: health concerns, schooling difficulties, social isolation and adjustment to restrictions. Health concerns included exacerbation of pre-existing health conditions, fear about the virus, difficulty getting children to understand the pandemic and increased sedentary behaviour. Schooling difficulties referred to the challenges of home schooling, which were behavioural (e.g. difficulty concentrating) and logistical (e.g. technology). Social isolation, expressed as missing friends, family and/or institutions was common. Finally, parents expressed that children experienced both positive adjustments to restrictions, such as spending more time with family, and negative adjustments such as increased screen time. Many responses from parents touched on topics across multiple themes, indicating a need for comprehensive, holistic assessment of children's and families' needs in the provision of support services. The content of the themes supports calls for resources to support children and families including increased financial and practical accessibility of social services, physical health and exercise support, mental health support and COVID-19 communication guides

Ionization potentials of fluoroindoles and the origin of nonexponential tryptophan fluorescence decay in proteins

This work reports an explanation for the unusual monoexponential fluorescence decay of 5-fluorotryptophan (5FTrp) in single-Trp mutant proteins [Broos, J.; Maddalena, F.; Hesp, B. H. J. Am. Chem. Soc. 2004, 126, 22-23] and substantially clarifies the origin of the ubiquitous nonexponential fluorescence decay of tryptophan in proteins. Our results strongly suggest that the extent of nonexponential fluorescence decay is governed primarily by the efficiency of electron transfer (ET) quenching by a nearby amide group in the peptide bond. Fluoro substitution increases the ionization potential (IP) of indole, thereby suppressing the ET rate, leading to a longer average lifetime and therefore a more homogeneous decay. We report experimental IPs for a number of substituted indoles including 5-fluoroindole, 5-fluoro-3-methylindole, and 6-fluoroindole, along with accurate ab initio calculations of the IPs for these and 20 related molecules. The results predict the IP of 5-fluorotryptophan to be 0.19 eV higher than that of tryptophan. 5-Fluoro substitution does not measurably alter the excitation-induced change in permanent dipole moment nor does it change the fluorescent state from L-1(a) to L-1(b). In combination with electronic structure information this argues that the increased I P and the decreased excitation energy of the L-1(a) state, together 0.3 eV, are solely responsible for the strong reduction of electron transfer quenching. 6-Fluoro substitution is predicted to increase the IP by a mere 0.09 eV. In agreement with our conclusions, the fluorescence decay curves of 6-fluorotryptophan-containing proteins are well fit using only two decay times compared to three required for Trp