Phenylalanine hydroxylase from
(CvPAH) is a monomeric enzyme that converts phenylalanine to tyrosine. It shares high amino acid identity and similar structure with a subunit of human phenylalanine ...hydroxylase that is a tetramer, resulting in the latent application in medications. In this study, semirational design was applied to CvPAH to improve the catalytic ability based on molecular dynamics simulation analyses. Four Nterminal truncated variants and one single point variant were constructed and characterized. The D267P variant showed a 2.1-fold increased thermal stability compared to the wild type, but lower specific activity was noted compared with the wild type. The specific activity of all truncated variants was a greater than 25% increase compared to the wild type, and these variants showed similar or slightly decreased thermostability with the exception of the N-Δ9 variant. Notably, the N-Δ9 variant exhibited a 1.2-fold increased specific activity, a 1.3-fold increased thermostability and considerably increased catalytic activity under the neutral environment compared with the wild type. These properties of the N-Δ9 variant could advance medical and pharmaceutical applications of CvPAH. Our findings indicate that the N-terminus might modulate substrate binding, and are directives for further modification and functional research of PAH and other enzymes.
Phenylalanine hydroxylase from Chromobacterium violaceum (CvPAH) is a monomeric enzyme that converts phenylalanine to tyrosine. It shares high amino acid identity and similar structure with a subunit ...of human phenylalanine hydroxylase that is a tetramer, resulting in the latent application in medications. In this study, semirational design was applied to CvPAH to improve the catalytic ability based on molecular dynamics simulation analyses. Four Nterminal truncated variants and one single point variant were constructed and characterized. The D267P variant showed a 2.1-fold increased thermal stability compared to the wild type, but lower specific activity was noted compared with the wild type. The specific activity of all truncated variants was a greater than 25% increase compared to the wild type, and these variants showed similar or slightly decreased thermostability with the exception of the N-Δ9 variant. Notably, the N-Δ9 variant exhibited a 1.2-fold increased specific activity, a 1.3-fold increased thermostability and considerably increased catalytic activity under the neutral environment compared with the wild type. These properties of the N-Δ9 variant could advance medical and pharmaceutical applications of CvPAH. Our findings indicate that the N-terminus might modulate substrate binding, and are directives for further modification and functional research of PAH and other enzymes.
HBx is a short-lived protein whose rapid turnover is mainly regulated by ubiquitin-dependent proteasomal degradation pathways. Our prior work identified BAF155 to be one of the HBx binding partners. ...Since BAF155 has been shown to stabilize other members of the SWI/SNF chromatin remodelling complex by attenuating their proteasomal degradation, we proposed that BAF155 might also contribute to stabilizing HBx protein in a proteasome-dependent manner. Here we report that BAF155 protected hepatitis B virus X protein (HBx) from ubiquitin-independent proteasomal degradation by competing with the 20S proteasome subunit PSMA7 to bind to HBx. BAF155 was found to directly interact with HBx via binding of its SANT domain to the HBx region between amino acid residues 81 and 120. Expression of either full-length BAF155 or SANT domain increased HBx protein levels whereas siRNA-mediated knockdown of endogenous BAF155 reduced HBx protein levels. Increased HBx stability and steady-state level by BAF155 were attributable to inhibition of ubiquitin-independent and PSMA7-mediated protein degradation. Consequently, overexpression of BAF155 enhanced the transcriptional transactivation function of HBx, activated protooncogene expression and inhibited hepatoma cell clonogenicity. These results suggest that BAF155 plays important roles in ubiquitin-independent degradation of HBx, which may be related to the pathogenesis and carcinogenesis of HBV-associated HCC.
•The oxidized tallow enriched the aroma of the Maillard reaction product;•Different oxidation of tallow produces different volatile compounds and flavors;•More free unsaturated fatty acids were ...produced by oxidation of tallow;•Associations were found between typical volatile products and sensory attributes.
This work investigated the effect of oxidized beef tallow on the volatile compositions and sensory properties of soybean meal-based Maillard reaction products (MRPs). Various tallow oxidation methods included thermal treatment (TT), enzymatic hydrolysis (ET) and enzymatic hydrolysis combined with mild thermal (ETT) treatment. Results showed that all these oxidized tallow contained more types of volatile compounds than those of untreated tallow. Moreover, the composition of almost all types of volatile substances was greatly increased with the addition of the oxidized beef tallow into the hydrolyzed soybean meal-based Maillard reaction system. More importantly, the composition of oxygen-containing heterocycles (63.89 μg/mL), sulfur-containing compounds (76.64 μg/mL), and nitrogen-containing heterocycles (19.81 μg/mL) that contribute positively to sensory properties in ETT-MRPs was found to be the highest among all the MRPs. Correlation assessment revealed that ETT was closely related to the most typical volatile products and sensory attributes, indicating this approach can effectively enhance the sensory and flavor of hydrolyzed soybean meal derived MRPs.
Chronic hepatitis B virus (HBV) infection is one of the major global health problems. Although the small protein of hepatitis B virus surface antigen (HBsAg), SHBs, is the most abundant HBV viral ...protein, its pathogenic role and molecular mechanism in malignant progression of HBV-related hepatocellular carcinoma (HCC) remain largely unknown. Here we reported that SHBs expression induced epithelial-mesenchymal transition (EMT) process in HCC cells and significantly increased their migratory and invasive ability as well as metastatic potential. Mechanistically, SHBs expression in HCC cells induced endoplasmic reticulum (ER) stress that activated the activating transcription factor 4 (ATF4) to increase the expression and secretion of fibroblast growth factor 19 (FGF19). The autocrine released FGF19 in turn activated JAK2/STAT3 signaling for induction of EMT process in HCC. Notably, SHBs was positively correlated with the expression of mesenchymal markers, the phosphorylation status of JAK2 and STAT3 as well as FGF19 levels in human HCC samples. HCC patients with SHBs positive had a more advanced clinical stage and worse prognosis. These results suggest an important role of SHBs in the metastasis and progression of HCC and may highlight a potential target for preventive and therapeutic intervention of HBV-related HCC and its malignant progression.
•SHBs induces EMT of HCC cells to promote their invasion and metastasis.•SHBs induces ER stress to activate transcription factor ATF4 for FGF19 upregulation.•SHBs enhances secretion of FGF19 that binds to FGFR4 to activate JAK2/STAT3 axis.•SHBs correlates with EMT and FGF19/JAK2/STAT3 signaling activation in HCC tissues.•HCC patients with SHBs positive had a more advanced clinical stage and worse prognosis.
The government’s development of eco-environmental policies can have a scientific foundation thanks to the fine particulate matter (PM
2.5
) medium- and long-term change forecast. This study develops ...a STRIPAT-Scenario analysis framework employing panel data from 11 cities in Zhejiang Province between 2006 and 2020 to predict the changing trend of PM
2.5
concentrations under five alternative scenarios. The results reveal that: (1) urbanization development (
P
), economic development (
A
), technological innovation investment (
T
) and environmental regulation intensity have a significant inhibitory effect on PM
2.5
concentration in Zhejiang Province, while industrial structure, industrial energy consumption and the number of motor vehicles (
TR
) have a significant increase on PM
2.5
concentration. (2) Under any scenario, the PM
2.5
concentration of 11 cities in Zhejiang Province can reach the constraint target set in the 14th Five-Year plan. The improvement in urban PM
2.5
quality is most obviously impacted by the high-quality development scenario (S4). (3) Toward 2035, PM
2.5
concentrations of 11 cities in Zhejiang Province can reach the National Class I level standard in most scenario models, among which Hangzhou, Jiaxing and Shaoxing are under high pressure to reduce emissions and are the key areas for PM
2.5
management in Zhejiang Province. However, most cities cannot reach the 10 μg/m
3
limit of WHO’s AQG2005 version. Finally, this study makes recommendations for reducing PM
2.5
in terms of enhancing industrial structure and funding science and technology innovation.
Single image dehazing is a challenging ill-posed task, we address it from the aspects of dehazing dataset and network architecture. As for the dehazing dataset, there are such problems as unnatural ...hazy images, unqualified ground truths, as well as monotonous and idealized depth-related haze synthesized by the physical model in the existing dehazing datasets. Therefore, we propose a novel haze data synthesis method to produce a dehazing dataset with non-homogeneous haze, which is named as FiveK-Haze. As for the network architecture, existing methods either get the image enhancement results directly in an end-to-end approach or restore the haze-free images based on the estimated physical parameters in a multiple-branch approach. To get better results for the real-world non-homogeneous haze images, we combine above two approaches together in a complementary way and design a new dehazing network with the enhancement-and-restoration fused CNNs, which is called as ERFNet. Exhaustive experimental results demonstrate the superiority of our method over the state-of-the-art methods in terms of both generalization performance and haze removal effects, especially for detail enhancement and color restoration.
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•We devise a haze data synthesis method to create a dehazing dataset named FiveK-Haze.•Our FiveK-Haze contains the synthesized hazy images with non-homogeneous haze.•We design the enhancement-and-restoration fused CNNs named ERFNet for image dehazing.•Our ERFNet combines the existing advantage-complementary two approaches together.•Our methods show advancement in generalization performance and dehazing effects.•Our methods show obvious advantages in detail enhancement and color restoration.
The government's development of eco-environmental policies can have a scientific foundation thanks to the fine particulate matter (PM
) medium- and long-term change forecast. This study develops a ...STRIPAT-Scenario analysis framework employing panel data from 11 cities in Zhejiang Province between 2006 and 2020 to predict the changing trend of PM
concentrations under five alternative scenarios. The results reveal that: (1) urbanization development (
), economic development (
), technological innovation investment (
) and environmental regulation intensity have a significant inhibitory effect on PM
concentration in Zhejiang Province, while industrial structure, industrial energy consumption and the number of motor vehicles (
) have a significant increase on PM
concentration. (2) Under any scenario, the PM
concentration of 11 cities in Zhejiang Province can reach the constraint target set in the 14th Five-Year plan. The improvement in urban PM
quality is most obviously impacted by the high-quality development scenario (S4). (3) Toward 2035, PM
concentrations of 11 cities in Zhejiang Province can reach the National Class I level standard in most scenario models, among which Hangzhou, Jiaxing and Shaoxing are under high pressure to reduce emissions and are the key areas for PM
management in Zhejiang Province. However, most cities cannot reach the 10 μg/m
limit of WHO's AQG2005 version. Finally, this study makes recommendations for reducing PM
in terms of enhancing industrial structure and funding science and technology innovation.
In proteins of thermophilic bacteria, Gly is tend to be replaced by Ala and Lys is tend to be replaced by Arg to adapt the high temperature. In order to improve the thermal stability of phenylalanine ...hydroxylase (PAH) from Chromobacterium violaceum, all the Gly on PAH were mutated to Ala and Lys to Arg. Positive mutant enzymes with improved thermal stability were selected, followed by combined mutation and characterization. The results revealed that half-lives of K94R and G221A mutants at 50 °C were 26.2 min and 16.8 min, which were increased by 1.9-times and 0.9-times than the parent enzyme (9.0 min). The residual activity of K94R/G221A mutant was improved to 65.6% after keeping at 50 °C for 1 h, which was 6.6 time higher than the parent enzyme (8.6%). Circular dichroism (CD) spectroscopy revealed that Tm values of the parent enzyme, K94R, G221A and K94R/G221A were 51.5 ℃, 53.8 ℃, 53.1 ℃ and 54.8 ℃, respectively. According to the protein structure simulation, the two mutations were located on flexible loop.
Background Musculoskeletal disorders are one of the most prevalent chronic diseases around the world. Additionally, they contribute significantly to the global burden of disease. Tuina manipulation ...played a crucial role in treating musculoskeletal diseases from ancient times to the present. However, there are no systematic investigations on the efficacy characteristics of Tuina manipulation for alleviating musculoskeletal pain. Objective To objective of the study was to investigate the factors that have an influence on the effectiveness of Tuina manipulation in treating musculoskeletal pain. Methods In October 2021, we interviewed physicians from Beijing's Tuina Department using the purpose sampling method and the snowball sampling strategy. Interviews were carried out following a semi-structured format to determine the factors influencing Tuina manipulation for musculoskeletal pain. In accordance with the study's aims, the interview outline was drafted and discussed with the research group, and the interview
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