Semiartificial Photosynthetic Nanoreactors for H Generation.

A relatively unexplored energy source in synthetic cells is transmembrane electron transport, which like proton and ion transport can be light driven. Here, synthetic cells, called nanoreactors, are engineered for compartmentalized, semiartificial photosynthetic H production by a [FeFe]-hydrogenase (Hase). Transmembrane electron transfer into the nanoreactor was enabled by MtrCAB, a multiheme transmembrane protein from MR-1.

The impact of school-based creative bibliotherapy interventions on child and adolescent mental health: a systematic review and realist synthesis protocol.

Background: There is a need to identify evidence-based interventions to be delivered in schools that can be used to improve child and adolescent mental health and wellbeing. Creative bibliotherapy is one proposed intervention. However, there has been, to date, no comprehensive assessment of the evidence for its impact on mental health and wellbeing.

Culturally sensitive neonatal palliative care: a critical review.

Although there are known disparities in neonatal and perinatal deaths across cultural groups, less is known about how cultural diversity impacts neonatal palliative care. This article critically reviews available literature and sets out key questions that need to be addressed to enhance neonatal palliative care provision for culturally diverse families. We begin by critically reviewing the challenges to recording, categorizing and understanding data which need to be addressed to enable a true reflection of the health disparities in neonatal mortality.

Light-Driven [FeFe] Hydrogenase Based H Production in : A Model Reaction for Exploring Based Semiartificial Photosynthetic Systems.

Biohybrid technologies like semiartificial photosynthesis are attracting increased attention, as they enable the combination of highly efficient synthetic light-harvesters with the self-healing and outstanding performance of biocatalysis. However, such systems are intrinsically complex, with multiple interacting components. Herein, we explore a whole-cell photocatalytic system for hydrogen (H) gas production as a model system for semiartificial photosynthesis.

Hydride state accumulation in native [FeFe]-hydrogenase with the physiological reductant H supports its catalytic relevance.

Small molecules in solution may interfere with mechanistic investigations, as they can affect the stability of catalytic states and produce off-cycle states that can be mistaken for catalytically relevant species. Here we show that the hydride state (H), a proposed central intermediate in the catalytic cycle of [FeFe]-hydrogenase, can be formed in wild-type [FeFe]-hydrogenases treated with H in absence of other, non-biological, reductants. Moreover, we reveal a new state with unclear role in catalysis induced by common low pH buffers.

Stability of the H-cluster under whole-cell conditions-formation of an H-like state and its reactivity towards oxygen.

Hydrogenases are metalloenzymes that catalyze the reversible oxidation of molecular hydrogen into protons and electrons. For this purpose, [FeFe]-hydrogenases utilize a hexanuclear iron cofactor, the H-cluster. This biologically unique cofactor provides the enzyme with outstanding catalytic activities, but it is also highly oxygen sensitive.

Lewis acid protection turns cyanide containing [FeFe]-hydrogenase mimics into proton reduction catalysts.

Sustainable sources of hydrogen are a vital component of the envisioned energy transition. Understanding and mimicking the [FeFe]-hydrogenase provides a route to achieving this goal. In this study we re-visit a molecular mimic of the hydrogenase, the propyl dithiolate bridged complex [Fe(μ-pdt)(CO)(CN)], in which the cyanide ligands are tuned Lewis acid interactions.

Characterization of a putative sensory [FeFe]-hydrogenase provides new insight into the role of the active site architecture.

[FeFe]-hydrogenases are known for their high rates of hydrogen turnover, and are intensively studied in the context of biotechnological applications. Evolution has generated a plethora of different subclasses with widely different characteristics. The M2e subclass is phylogenetically distinct from previously characterized members of this enzyme family and its biological role is unknown.

[FeFe]-hydrogenase maturation: H-cluster assembly intermediates tracked by electron paramagnetic resonance, infrared, and X-ray absorption spectroscopy.

[FeFe]-hydrogenase enzymes employ a unique organometallic cofactor for efficient and reversible hydrogen conversion. This so-called H-cluster consists of a [4Fe-4S] cubane cysteine linked to a diiron complex coordinated by carbon monoxide and cyanide ligands and an azadithiolate ligand (adt = NH(CHS))·[FeFe]-hydrogenase apo-protein binding only the [4Fe-4S] sub-complex can be fully activated in vitro by the addition of a synthetic diiron site precursor complex ([2Fe]). Elucidation of the mechanism of cofactor assembly will aid in the design of improved hydrogen processing synthetic catalysts.

Spectroscopic investigations under whole-cell conditions provide new insight into the metal hydride chemistry of [FeFe]-hydrogenase.

Hydrogenases are among the fastest H evolving catalysts known to date and have been extensively studied under conditions. Here, we report the first mechanistic investigation of an [FeFe]-hydrogenase under whole-cell conditions. Functional [FeFe]-hydrogenase from the green alga is generated in genetically modified cells by addition of a synthetic cofactor to the growth medium.

Discovery of novel [FeFe]-hydrogenases for biocatalytic H-production.

A new screening method for [FeFe]-hydrogenases is described, circumventing the need for specialized expression conditions as well as protein purification for initial characterization. [FeFe]-hydrogenases catalyze the formation and oxidation of molecular hydrogen at rates exceeding 10 s, making them highly promising for biotechnological applications. However, the discovery of novel [FeFe]-hydrogenases is slow due to their oxygen sensitivity and dependency on a structurally unique cofactor, complicating protein expression and purification.

The reactivity of molecular oxygen and reactive oxygen species with [FeFe] hydrogenase biomimetics: reversibility and the role of the second coordination sphere.

The development of oxygen-tolerant H2-evolving catalysts plays a vital role for a future H2 economy. For example, the [FeFe] hydrogenase enzymes are excellent catalyst for H2 evolution but rapidly become inactivated in the presence of O2. The mechanistic details of the enzyme's inactivation by molecular oxygen still remain unclear.

Synthesis of a miniaturized [FeFe] hydrogenase model system.

The reaction occurring during artificial maturation of [FeFe] hydrogenase has been recreated using molecular systems. The formation of a miniaturized [FeFe] hydrogenase model system, generated through the combination of a [4Fe4S] cluster binding oligopeptide and an organometallic Fe complex, has been monitored by a range of spectroscopic techniques. A structure of the final assembly is suggested based on EPR and FTIR spectroscopy in combination with DFT calculations.

Monitoring H-cluster assembly using a semi-synthetic HydF protein.

The [FeFe] hydrogenase enzyme interconverts protons and molecular hydrogen with remarkable efficiency. The reaction is catalysed by a unique metallo-cofactor denoted as the H-cluster containing an organometallic dinuclear Fe component, the [2Fe] subsite. The HydF protein delivers a precursor of the [2Fe] subsite to the apo-[FeFe] hydrogenase, thus completing the H-cluster and activating the enzyme.

Identification of the HLA-Cw*0774 and DQB1*060105 alleles.

Cw*0774 differs from Cw*070201 by one nucleotide within the coding sequence of exons 2-4. DQB1*060105 differs from DQB1*060101 by one nucleotide within the coding sequence of exons 2-3.

A novel HLA-B*44 allele, B*4466, discovered in a potential donor for a hematopoietic stem cell transplant.

This report describes the discovery and characterization of the human leukocyte antigen-B*4466 allele.

Discovery of a novel HLA-Cw*08 allele, Cw*0817.

This report describes the discovery and characterization of the HLA-Cw*0817 allele.

A novel HLA-Cw*05 allele, Cw*0517.

This report describes the discovery and characterization of the HLA-Cw*0517 allele.

A novel HLA-C locus allele with codon 54 deletion, Cw*0346.

This report describes the discovery and characterization of the novel Cw*0346 allele.

A novel HLA-B*51 allele, HLA-B*5149.

Discovery of the novel HLA-B*5149 allele in a North American Caucasian individual is described. It differs from B*510101 by one nucleotide within the coding sequence of exons 1-6. A substitution at nucleotide position 488 in exon 3 changes alanine to glycine in amino acid position 139.