Crystallographic characterization of ferritin from Sinonovacula constricta.

Ferritins are ubiquitous iron-binding proteins that are mainly related to iron storage, detoxification and innate immunity. Here, we present the crystal structure of a marine invertebrate ferritin from Sinonovacula constricta at a resolution of 1.98 Å. The S. constricta ferritin (ScFer) possessed some structural similarities with vertebrate ferritins, and they shared a well-conserved architecture composed of five α-helical bundles that assembled into a cage-like structure with 24-subunits. The structure of ScFer also showed iron binding sites in the 3-fold channel, ferroxidase center, and putative nucleation sites. Further, electrostatic potential calculations suggested that the electrostatic gradient of the 3-fold channel could provide a guidance mechanism for iron entering the ferritin cavity.

IFITM3 restricts porcine deltacoronavirus infection by targeting its Spike protein.

The discovery of antiviral molecules is crucial for controlling porcine deltacoronavirus (PDCoV). Previous studies have provided evidence that the IFN-inducible transmembrane protein 3 (IFITM3), which is coded by an interferon-stimulated gene, prevents the infections of a number of enveloped viruses. Nevertheless, the involvement of IFITM3 in PDCoV infection remains unexplored. In this study, it was observed that the overexpression of IFITM3 successfully restrictes the infection of PDCoV in cell cultures. Conversely, the suppression of IFITM3 facilitates the infection of PDCoV in IPI-2I and IPEC-J2 cells. Further studies revealed that IFITM3 limits the attachment phase of viral infection by interacting with the S1 subunit of the PDCoV Spike (S) protein. In addition, IFITM3 is verified as a member of the CD225 family, the GxxxG conserved motif of this family is important for it to limit PDCoV infection. In summary, this study reveals the mechanism of IFITM3 as an antiviral molecule to inhibit PDCoV infection, and also provides theoretical supports for screening effective anti-PDCoV drugs.

Distribution, contamination and provenance of heavy metals in sediments from the nearshore area of Weihai City, eastern Shandong Peninsula, China.

We analyzed eight heavy metals (Cu, Pb, Zn, Cr, Cd, Hg, As, and Ni) in 85 seabed sediments off the coast of Weihai City, eastern Shandong Peninsula, China, to reveal their distributions, enrichment status, and pollutant sources. Cu, Pb, Zn, Cr, As, and Ni were enriched in all bays in both the inner and outer waters. However, Cd and Hg were more abundant in Weihai Bay, followed by Rongcheng Bay and Chaoyang Port, with denser populations and more developed industries near the coast. Most areas exhibited slight contamination with As and Pb, with relatively severe contamination in localized areas. Moreover, Weihai Bay showed slight contamination with Cd, Zn, and Hg. Heavy metals are largely influenced by the discharge of anthropogenic pollutants along the coast. It is recommended to implement strict control measures on the discharge of waste into the sea, and ensure the sustainable development of the marine ecological environment.

Distribution, enrichment and source of heavy metals in Rizhao offshore area, southeast Shandong Province.

50 surface sediments were collected from Rizhao offshore area to determine heavy metals (Cu, Pb, Zn, Cr, Cd, As, Hg) pollution. High heavy metal values were located near the two ports in the north and south study areas, which was consistent with the distribution of fine-grained sediments. According to threshold effect level (TEL) and probable effect level (PEL), Cu and As had occasionally adverse biological effects on the aquatic ecosystems. The enrichment factor (EF) values showed that most of the study area was moderate or moderately severe enrichment for As, and minor enrichment for Pb, but Hg was only moderately enriched in the river estuaries. The sources of Cu, Zn and Cr were mainly influenced by natural weathering processes via the river inputs, whereas Pb, Cd and As were mainly derived from anthropogenic sources. Hg may have both natural and anthropogenic sources.

Distribution and contamination assessment of heavy metals in surface sediments of the Luanhe River Estuary, northwest of the Bohai Sea.

33 surface sediment samples from the Luanhe River Estuary have been analyzed for heavy metals to evaluate the spatial distribution pattern and their potential ecological risk. Higher metal concentrations were found in the river mouth and southern areas where being covered by fine particulate matters. In comparison with the threshold effect level and the probable effect level, Cu, Pb, Cr, Ni, and As had occasionally adverse biological effects on the aquatic ecosystems. Both the enrichment factor and geoaccumulation index values show that all the regions have been weakly polluted by Pb, Hg, As, and Cd with an exception of being moderately to strongly polluted by Hg in the river mouth and southern areas. The sources of Zn, Ni, Cd, Hg, and Cr were mainly from the river input and coastal discharge, whereas Cu, Pb, and As were mainly derived from vehicle emissions, coal and oil combustion.