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The flavoprotein Cytochrome P450 reductase (CPR) is the unique electron pathway from NADPH to Cytochrome P450 (CYPs). The conformational dynamics of human CPR in solution, which involves transitions from a "locked/closed" to an "unlocked/open" state, is crucial for electron transfer. To date, however, the factors guiding these changes remain unknown. By Site‐Directed Spin Labelling coupled to Electron Paramagnetic Resonance spectroscopy, we have incorporated a non‐canonical amino acid onto the flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD) domains of soluble human CPR, and labelled it with a specific nitroxide spin probe. Taking advantage of the endogenous FMN cofactor, we successfully measured for the first time, the distance distribution by DEER between the semiquinone state FMNH• and the nitroxide. The DEER data revealed a salt concentration‐dependent distance distribution, evidence of an "open" CPR conformation at high salt concentrations exceeding previous reports. We also conducted molecular dynamics simulations which unveiled a diverse ensemble of conformations for the "open" semiquinone state of the CPR at high salt concentration. This study unravels the conformational landscape of the one electron reduced state of CPR, which had never been studied before. [ABSTRACT FROM AUTHOR]

Ireland has among the lowest rates of breastfeeding worldwide. Despite policies to support breastfeeding, breastfeeding initiation and exclusivity remain low in Ireland. Greater knowledge about support received in the maternity unit may—in part—shed light on why this is so. Our aim was to analyse women's experiences of the breastfeeding supports available in the early postnatal period in Ireland. We conducted an analysis of an open-ended question on a cross-sectional survey about breastfeeding support conducted in the Republic of Ireland in 2022. Participants were asked to provide comments about the breastfeeding support they received in the maternity unit or during your home birth. Data were analysed using Braun and Clarke's six-step Thematic Analysis Framework. There were 5,412 unique responses to the survey and 2,264 responses to the question of interest. Two themes were generated from the data: (i) 'Breastfeeding support in theory but not in practice.' Although breastfeeding was promoted by healthcare professionals antenatally, breastfeeding challenges were rarely mentioned. Participants then felt unsupported in overcoming challenges postnatally. (ii) 'Support was either inaccessible due to lack of staff/time, inadequate; i.e., unhelpful or non-specific, and/or physically inappropriate.' Most participants described receiving supports that were less than optimal in aiding them to establish breastfeeding. While many described difficulties in accessing supports, others found support to be 'non-specific,' 'rushed' and sometimes 'rough.' A lack of knowledge, time and support from healthcare professionals was frequently described, which was often recognised as a failing of the healthcare system. Women require practical, informative, and specific breastfeeding support. Barriers such as lack of time and trained staff in the maternity unit need to be addressed. [ABSTRACT FROM AUTHOR]

The article presents the discussion on nurses responsible for assisting patients in end-of-life decision-making and goals of care conversations including undergraduate nursing students to developing competency in advance care planning (ACP).

S100A1 is a member of the S100 family of small ubiquitous Ca2+-binding proteins, which participates in the regulation of cell differentiation, motility, and survival. It exists as homo- or heterodimers. S100A1 has also been shown to bind Zn2+, but the molecular mechanisms of this binding are not yet known. In this work, using ESI-MS and ITC, we demonstrate that S100A1 can coordinate 4 zinc ions per monomer, with two high affinity (KD~4 and 770 nm) and two low affinity sites. Using competitive binding experiments between Ca2+ and Zn2+ and QM/MM molecular modeling we conclude that Zn2+ high affinity sites are located in the EF-hand motifs of S100A1. In addition, two lower affinity sites can bind Zn2+ even when the EF-hands are saturated by Ca2+, resulting in a 2Ca2+:S100A1:2Zn2+ conformer. Finally, we show that, in contrast to calcium, an excess of Zn2+ produces a destabilizing effect on S100A1 structure and leads to its aggregation. We also determined a higher affinity to Ca2+ (KD~0.16 and 24 μm) than was previously reported for S100A1, which would allow this protein to function as a Ca2+/Zn2+-sensor both inside and outside cells, participating in diverse signaling pathways under normal and pathological conditions. [ABSTRACT FROM AUTHOR]

We have discovered a protein with an amino acid composition exceptionally rich in glycine and cysteine residues in the giant virus mimivirus. This small 6 kDa protein is among the most abundant proteins in the icosahedral 0.75 μm viral particles; it has no predicted function but is probably essential for infection. The aerobically purified red-brownish protein overproduced in Escherichia coli contained both iron and inorganic sulfide. UV/vis, EPR, and Mössbauer studies revealed that the viral protein, coined GciS, accommodated two distinct Fe-S clusters: a diamagnetic S = 0 [2Fe-2S] 2+ cluster and a paramagnetic S = 5/2 linear [3Fe-4S] 1+ cluster, a geometry rarely stabilized in native proteins. Orthologs of mimivirus GciS were identified within all clades of Megavirinae , a Mimiviridae subfamily infecting Acanthamoeba , including the distantly related tupanviruses, and displayed the same spectroscopic features. Thus, these glycine/cysteine-rich proteins form a new family of viral Fe-S proteins sharing unique Fe-S cluster binding properties.