Zhibiao Feng,Lele Li,Yu Zhang,Xuan Li,Chunhong Liu,Bin Jiang,Jing Xu,Zhigang Sun
Nanofibrils have favorable functional properties that facilitate their applications in the food industry. Whey protein isolate (WPI) is widely used to prepare nanofibrils via acid hydrolysis. In this research, the effect of hydrolysis by endoproteinase GluC (GluC) on WPI nanofibrils (WPNFs) was evaluated based on their structural and emulsifying properties. Following the hydrolysis of WPI by GluC at 37 °C and pH 8.0, the peptides self-assembled into WPNFs at 37 °C and pH 2.0. WPNFs with several micrometric length and nanometric (1–10 nm) diameter exhibited high aspect ratio (length/diameter). Based on microscopic images, circular dichroism spectroscopy , and infrared spectroscopy , we concluded that β-sheets played an important role in the formation and stability of WPNFs. The main factor affecting WPNF formation was found to be hydrolysis by GluC for 10 h followed by aggregation at pH 2.0. Whey protein hydrolysates with glutamic acid or aspartic acid residues, obtained from WPI hydrolysis by GluC for 10 h, might be positively charged in an acidic environment, thereby favoring the formation of ordered aggregates instead of random ones. WPNFs prepared under such conditions have a strong ability of improving the oxidative stability, activity and stability of emulsions . This new strategy for producing WPNFs will potentially expand their application in the food industry.
Moxuan Ji,Xinan Wang,Haifeng Zheng,Wenjie Mao,Xiaorui Shi,Si Chen,Chu Tang,Fu Wang
Pyroptotic cell death is a phenomenon that runs through all life activities and plays an important role in physiological and pathological processes of the body’s metabolism. It is of big biological significance to understand the phenomenon and nature of cell pyroptosis. In the process of cell pyroptosis, the pore-forming effector gasdermin D (GSDMD) is cleaved to form oligomers, which are inserted into the cell membrane, causing rapid cell death. However, the effective cell death induced by GSDMD complicates our ability to understand the behavior of pyroptosis. In this work, we performed molecular mutagenesis to develop a genetically encoded pyroptotic reporter, where a secreted Gaussia luciferase (Gluc) was strategically placed in the p30-p20 tolerated junction of GSDMD to support natural pyrophosphorylation and promote live imaging of cell pyroptosis. In addition, we demonstrated that this fused Gluc-GSDMD reporter executed inflammatory body-dependent pyroptosis in response to extracellular stimuli, and that the lysed p30-GSDMD can be secreted out of the cell and can be detected in the culture medium and animal blood. Therefore, our study provides a valuable tool that not only noninvasive and real-time monitoring of cell pyroptosis, but also affords a high-throughput functional screening of pyroptosis-targeted compounds in cultured cells and animal models.
Feline herpesvirus type 1 (FHV-1), a member of the Herpesviridae family, is one of the most important pathogens that causes upper respiratory tract disease in felines. Following infection, FHV-1 can spread retrogradely to the trigeminal ganglia, establishing a life-long latency. Although vaccines are available for routine feline vaccination, FHV-1 is still an agent that poses a serious threat to feline health. There are currently no specific drugs for the treatment of FHV-1. To facilitate the screening of antiviral drugs, we constructed a reporter FHV-1 virus, which expresses a secreted Gaussia luciferase (GLuc) and a bright green fluorescent protein, mNeonGreen. The reporter virus shows slower growth than does the wild-type FHV-1. The expression of the two reporter genes, Gluc and mNeonGreen, was consistent with viral propagation and remained stable during continuous passage in CRFK cells, even after twenty rounds. In addition, the known inhibitor ganciclovir was used to confirm the characteristics of the reporter virus for drug screening. We found that the reporter FHV-1 is suitable for antiviral screening assays. Overall, our work provides a useful tool for screening drugs to combat FHV-1.
危险品化学品经营许可证（带存储）