► Skipjack roe hydrolysate was able to scavenge several radicals. ► Interfacial properties of hydrolysate were governed by DH. ► Antioxidative peptides had MW of 57.8 and 5.5kDa.
Antioxidative and ...functional properties of protein hydrolysate from defatted skipjack (Katsuwonous pelamis) roe, hydrolysed by Alcalase 2.4L (RPH) with different degrees of hydrolysis (DH) at various concentrations were examined. As DH increased, the reduction of DPPH, ABTS radicals scavenging activities and reducing power were noticeable (p<0.05). The increases in metal chelating activity and superoxide scavenging activity were attained with increasing DH (p<0.05). However, chelating activity gradually decreased at DH above 30%. All activities except superoxide anion radical scavenging activity increased as the concentration of hydrolysate increased (p<0.05). Hydrolysis using Alcalase could increase protein solubility to above 80% over a wide pH range (2–10). The highest emulsion ability index (EAI) and foam stability (FS) of hydrolysates were observed at low DH (5%) (p<0.05). Concentrations of hydrolysates determined interfacial properties differently, depending on DH. The molecular weight distribution of RPH with 5%DH (RPH5) was determined using Sephadex G-75 column. Two major peaks with the molecular weight of 57.8 and 5.5kDa were obtained. Fraction with MW of 5.5 had the strongest metal chelating activity and ABTS radical scavenging activity. The results reveal that protein hydrolysates from defatted skipjack roe could be used as food additives possessing both antioxidant activity and functional properties.
IRW is an egg ovotransferrin-derived ACE inhibitory peptide. The purpose of this study was to evaluate the stability and transcellular transport of IRW in Caco-2 cell monolayers. The stability of IRW ...was monitored on the apical (AP) surface while its transport was studied from AP to basal (BL) and from BL to AP surfaces. The results revealed that IRW is resistant against intestinal peptidase up to 60 min. Transport of IRW was not affected by addition of wortamanin, a transcytosis inhibitor. However, in the presence of cytochalasin D, a gap junction disruptor, transport of IRW was significantly increased, suggesting a possible passive transport from AP to BL surface. A higher transport of IRW from AP to BL surface than that from BL to AP surface suggests a passive-mediated transport. Moreover, in the presence of glycyl-sarcosine, a substrate for peptide transporter PepT 1, transport of IRW was reduced from AP to BL surface. The above observations showed atypical transport of IRW in Caco-2 cell monolayers. Thus, IRW may possibly be absorbed intact into the site of action for controlling hypertension.
The nighttime light data records artificial light on the Earth's surface and can be used to estimate the spatial distribution of the gross domestic product (GDP) and the electric power consumption ...(EPC). In early 2013, the first global NPP-VIIRS nighttime light data were released by the Earth Observation Group of National Oceanic and Atmospheric Administration's National Geophysical Data Center (NOAA/NGDC). As new-generation data, NPP-VIIRS data have a higher spatial resolution and a wider radiometric detection range than the traditional DMSP-OLS nighttime light data. This study aims to investigate the potential of NPP-VIIRS data in modeling GDP and EPC at multiple scales through a case study of China. A series of preprocessing procedures are proposed to reduce the background noise of original data and to generate corrected NPP-VIIRS nighttime light images. Subsequently, linear regression is used to fit the correlation between the total nighttime light (TNL) (which is extracted from corrected NPP-VIIRS data and DMSP-OLS data) and the GDP and EPC (which is from the country's statistical data) at provincial- and prefectural-level divisions of mainland China. The result of the linear regression shows that R2 values of TNL from NPP-VIIRS with GDP and EPC at multiple scales are all higher than those from DMSP-OLS data. This study reveals that the NPP-VIIRS data can be a powerful tool for modeling socioeconomic indicators; such as GDP and EPC.
Poverty has appeared as one of the long-term predicaments facing development of human society during the 21st century. Estimation of regional poverty level is a key issue for making strategies to ...eliminate poverty. This paper aims to evaluate the ability of the nighttime light composite data from the Visible Infrared Imaging Radiometer Suite (VIIRS) Day-Night Band (DNB) carried by the Suomi National Polar-orbiting Partnership (NPP) Satellite in estimating poverty at the county level in China. Two major experiments are involved in this study, which include 1) 38 counties of Chongqing city and 2) 2856 counties of China. The first experiment takes Chongqing as an example and combines 10 socioeconomic variables into an integrated poverty index (IPI). IPI is then used as a reference to validate the accuracy of poverty evaluation using the average light index (ALI) derived from NPP-VIIRS data. Linear regression and comparison of the class ranks have been employed to verify the correlation between ALI and IPI. The results show a good correlation between IPI and ALI, with a coefficient of determination (R 2 ) of 0.8554, and the class ranks of IPI and API show relative closeness at the county level. The second experiment examines all counties in China and makes a comparison between ALI values and national poor counties (NPC). The comparison result shows a general agreement between the NPC and the counties with low ALI values. This study reveals that the NPP-VIIRS data can be a useful tool for evaluating poverty at the county level in China.
The pandemic of COVID-19, caused by SARS-CoV-2, is a major global health threat. Epidemiological studies suggest that bats (
) are the natural zoonotic reservoir for SARS-CoV-2. However, the host ...range of SARS-CoV-2 and intermediate hosts that facilitate its transmission to humans remain unknown. The interaction of coronavirus with its host receptor is a key genetic determinant of host range and cross-species transmission. SARS-CoV-2 uses angiotensin-converting enzyme 2 (ACE2) as the receptor to enter host cells in a species-dependent manner. In this study, we characterized the ability of ACE2 from diverse species to support viral entry. By analyzing the conservation of five residues in two virus-binding hotspots of ACE2 (hotspot 31Lys and hotspot 353Lys), we predicted 80 ACE2 proteins from mammals that could potentially mediate SARS-CoV-2 entry. We chose 48 ACE2 orthologs among them for functional analysis, and showed that 44 of these orthologs-including domestic animals, pets, livestock, and animals commonly found in zoos and aquaria-could bind the SARS-CoV-2 spike protein and support viral entry. In contrast, New World monkey ACE2 orthologs could not bind the SARS-CoV-2 spike protein and support viral entry. We further identified the genetic determinant of New World monkey ACE2 that restricts viral entry using genetic and functional analyses. These findings highlight a potentially broad host tropism of SARS-CoV-2 and suggest that SARS-CoV-2 might be distributed much more widely than previously recognized, underscoring the necessity to monitor susceptible hosts to prevent future outbreaks.
RyR2 is a high-conductance intracellular calcium (Ca
) channel that controls the release of Ca
from the sarco(endo)plasmic reticulum of a variety of cells. Here, we report the structures of RyR2 from ...porcine heart in both the open and closed states at near-atomic resolutions determined using single-particle electron cryomicroscopy. Structural comparison reveals a breathing motion of the overall cytoplasmic region resulted from the interdomain movements of amino-terminal domains (NTDs), Helical domains, and Handle domains, whereas almost no intradomain shifts are observed in these armadillo repeats-containing domains. Outward rotations of the Central domains, which integrate the conformational changes of the cytoplasmic region, lead to the dilation of the cytoplasmic gate through coupled motions. Our structural and mutational characterizations provide important insights into the gating and disease mechanism of RyRs.
Egg proteins are important components for the development of functional foods and nutraceuticals. This study investigated the oxygen radical-scavenging effects of egg white protein ovotransferrin ...(including the whole protein, thermolysin–pepsin hydrolysate, and its bioactive peptides) and their interactions with four phytochemicals (vitamin C, epigallocatechin gallate (EGCG), caffeic acid, and quercetin), based on the oxygen radical absorbance capacity (ORAC) assay. The results showed that the hydrolysate possessed significantly higher oxygen radical absorbance capacity than the whole protein. The peptide IRW possessed very strong oxygen radical-scavenging effect, which might be attributed to its constitutive amino acid tryptophan (W) and the peptide bond between arginine (R) and W. Both the hydrolysate and the whole protein of ovotransferrin showed negative effects on four phytochemicals. However, the interactions between peptides/amino acids and the four phytochemicals are complex: some are positive, while others are negative. The results suggest that not only the phytochemicals, but also the hydrolysates or the peptides from the egg proteins could be a potential source of natural antioxidants.
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•Thermoase and pepsin-digested pea protein hydrolysate showed ACE2 up-regulating property in vascular smooth muscle cells.•A peptide with the sequence of AKSLSDRFSY was characterized ...from pea protein hydrolysate as an ACE2 up-regulator.•LSDRFS and SDRFSY identified from AKSLSDRFSY digests showed comparable activity as the parent peptide.
Angiotensin converting enzyme 2 (ACE2) degrades vasoconstricting angiotensin II (Ang II) into angiotensin (1–7), exerting protective effects in cardiovascular system; thus, ACE2 is considered as a novel target for cardiovascular therapy. The objectives of this study were to identify ACE2 up-regulating peptides from pea protein hydrolysate based on activity-guided purification. Pea protein hydrolysate prepared by a combination of thermoase and pepsin was subjected to various chromatographic fractionation; a peptide with the sequence of AKSLSDRFSY was identified as a novel ACE2 up-regulating peptide. AKSLSDRFSY was resistant to pepsin but not pancreatin in an in vitro digestion system. The resulting new sequences after digestion were characterized. Fragments with the sequences of LSDRFS and SDRFSY showed comparable effects in up-regulating ACE2 expression in vascular smooth muscle cells as the parent peptide. Future study will evaluate in vivo efficacy of the characterized pea protein-derived peptides.
The Xiaojiang fault zone system (XJFS) is located in the southeastern Tibet with high seismicity. In this study, we invert Rayleigh and Love wave dispersion curves obtained from three dense seismic ...arrays jointly for high-resolution 3-D crustal average shear wave velocity and radial anisotropy models simultaneously in XJFS. Our model reveals that the upper crust and mid-lower crust generally exhibit negative and positive radial anisotropy, respectively, implying that the deformation pattern is depth-dependent. To the east of the Lvzhijiang Fault, most of the low velocity zones in the mid-crust correspond to the positive radial anisotropy (Vsh > Vsv); the channelized weak zone seems to be continuous across the Red River Fault at depth of 20 km, probably within a thin layer. West of the Lvzhijiang Fault, where it is inferred to be the inner zone of the Permian Emeishan Large Igneous Province, the high velocity zone and positive radial anisotropy in the mid-lower crust can be attributed to the underplating and intruded magmatic rocks. In the upper crust, the high and low velocity zones are mostly belt-shape and follow the north-south direction parallel to the regional major faults; the lateral variation of the radial anisotropy spatially corresponds to the activity of different segments of the Xiaojiang fault zone. Our models depict detailed geometry of the channelized weak zone in the mid-lower crust and provide new insight into the role of major faults in regional tectonics.
•High-precision crustal Vs and radial anisotropy models in XJFS (SE Tibet) are derived.•Our models depict detailed geometry of the channelized weak zone in mid-lower crust.•Radial anisotropy is spatially associated with activity of different segments of XJF.
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