Genomic structure of human lysosomal glycosylasparaginase

AbstractThe gene structure of the human lysosomal enzyme glycosylasparaginase was determined. The gene spans 13 kb and consists of 9 exons. Both 5′ and 3′ untranslated regions of the gene are uninterrupted by introns. A number of transcriptional elements were identified in the 5′ upstream sequence that includes two putative CAAT boxes followed by TATA-like sequences together with two AP-2 binding sites and one for Sp1. A 100 bp CpG island and several ETF binding sites were also found. Additional AP-2 and Sp1 binding sites are present in the first intron. Two polyadenylation sites are present and appear to be functional. The major known glycosylasparaginase gene defect G488→C, which causes the lysosomal storage disease aspartylglycosaminuria (AGU) in Finland, is located in exon 4. Exon 5 encodes the post-translational cleavage site for the formation of the mature α/β subunits of the enzyme as well as a recently proposed active site threonine, Thr206

Controllable Tailoring Graphene Nanoribbons with Tunable Surface Functionalities: An Effective Strategy toward High-Performance Lithium-Ion Batteries

An effective, large-scale synthesis strategy for producing graphene nanoribbons (GNRs) with a nearly 100% yield has been proposed using a stepwise, solution-based, lengthwise unzipping carbon nanotube (CNT) method. Detailed Raman and X-ray photoelectron spectroscopy (XPS) analysis suggest that GNRs with tunable density of oxygen-containing functional groups on the GNR surfaces can be synthesized by adjusting the oxidant concentration during the CNT unzipping. The electrochemical characterization reveals that the as-produced GNRs with 42.91 atomic percent (atom %) oxygen-containing functional groups deliver a capacity of 437 mAh g^–1 after 100 cycles at 0.33C, while the as-produced GNRs with higher oxygen-containing functional groups only present a capacity of 225 mAh g^–1. On the basis of the electrochemical assessment and XPS analysis, the funtionals groups (epoxy-, carbonyl-, and carboxyl groups) in GNRs could be the effective contributor for the high-performance Li-ion batteries with appropriate adjustment

Rational Design of Cobalt–Iron Selenides for Highly Efficient Electrochemical Water Oxidation

Exploring active, stable, earth-abundant, low-cost, and high-efficiency electrocatalysts is highly desired for large-scale industrial applications toward the low-carbon economy. In this study, we apply a versatile selenizing technology to synthesize Se-enriched Co_1–<i>x</i>Fe_<i>x</i>Se₂ catalysts on nickel foams for oxygen evolution reactions (OERs) and disclose the relationship between the electronic structures of Co_1–<i>x</i>Fe_<i>x</i>Se₂ (via regulating the atom ratio of Co/Fe) and their OER performance. Owing to the fact that the electron configuration of the Co_1–<i>x</i>Fe_<i>x</i>Se₂ compounds can be tuned by the incorporated Fe species (electron transfer and lattice distortion), the catalytic activity can be adjusted according to the Co/Fe ratios in the catalyst. Moreover, the morphology of Co_1–<i>x</i>Fe_<i>x</i>Se₂ is also verified to strongly depend on the Co/Fe ratios, and the thinner Co_0.4Fe_0.6Se₂ nanosheets are obtained upon selenization treatment, in which it allows more active sites to be exposed to the electrolyte, in turn promoting the OER performance. The Co_0.4Fe_0.6Se₂ nanosheets not only exhibit superior OER performance with a low overpotential of 217 mV at 10 mA cm^–2 and a small Tafel slope of 41 mV dec^–1 but also possess ultrahigh durability with a dinky degeneration of 4.4% even after 72 h fierce water oxidation test in alkaline solution, which outperforms the commercial RuO₂ catalyst. As expected, the Co_0.4Fe_0.6Se₂ nanosheets have shown great prospects for practical applications toward water oxidation

A Universal Method to Engineer Metal Oxide–Metal–Carbon Interface for Highly Efficient Oxygen Reduction

Oxygen is the most abundant element in the Earth’s crust. The oxygen reduction reaction (ORR) is also the most important reaction in life processes and energy converting/storage systems. Developing techniques toward high-efficiency ORR remains highly desired and a challenge. Here, we report a N-doped carbon (NC) encapsulated CeO₂/Co interfacial hollow structure (CeO₂–Co–NC) <i>via</i> a generalized strategy for largely increased oxygen species adsorption and improved ORR activities. First, the metallic Co nanoparticles not only provide high conductivity but also serve as electron donors to largely create oxygen vacancies in CeO₂. Second, the outer carbon layer can effectively protect cobalt from oxidation and dissociation in alkaline media and as well imparts its higher ORR activity. In the meanwhile, the electronic interactions between CeO₂ and Co in the CeO₂/Co interface are unveiled theoretically by density functional theory calculations to justify the increased oxygen absorption for ORR activity improvement. The reported CeO₂–Co–NC hollow nanospheres not only exhibit decent ORR performance with a high onset potential (922 mV <i>vs</i> RHE), half-wave potential (797 mV <i>vs</i> RHE), and small Tafel slope (60 mV dec^–1) comparable to those of the state-of-the-art Pt/C catalysts but also possess long-term stability with a negative shift of only 7 mV of the half-wave potential after 2000 cycles and strong tolerance against methanol. This work represents a solid step toward high-efficient oxygen reduction