The secondary structure of heated whey protein and its hydrolysates antigenicity

Fourier transform infrared spectroscopy(FTIR) and circular dichroism(CD) were used to investigate the conformational changes of heated whey protein(WP) and the corresponding changes in the hydrolysates immunoreactivity were determined by competitive enzyme-linked immunosorbent assay(ELISA).Results showed that the contents of α-helix and β-sheet of WP did not decrease much under mild heating conditions and the antigenicity was relatively high;when the heating intensity increased(70 ℃ for 25 min or 75 ℃ for 2...     

Effect of ultrasonic-ionic liquid pretreatment on the hydrolysis degree and antigenicity of enzymatic hydrolysates from whey protein

With the aim to reduce the antigenicity of whey protein hydrolysate in milk, the pretreatment method of coupling ultrasonic and ionic liquid (US-IL) and further enzymatic treatments were studied. Papain and alcalase were found to be suitable for ultrasonic-ionic liquid pretreatment. After ultrasound-ionic liquid treatment, the antigenic decline rates of ALA and BLG upon alcalase hydrolysis were 82.82% and 88.01%, and that of the papain hydrolysis was 81.87% and 88.46%, respectively. Upon ultrasonic-ionic liquid pretreatment, the molecular weight of whey protein did not change significantly, but the small molecular weight proportion of components in the enzymatic hydrolysate obviously increased. The findings showed that combining with US-IL pretreatment for further protease hydrolysis of whey proteins, the hydrolysate can be used in order to produce hypoallergenic bovine whey proteins.     

Immunopeptidome screening to design An immunogenic construct against PRAME positive breast cancer; An in silico study

BackgroundMetastasis is the main cause of breast cancer (BC) lethality, especially in early stages, led to improvements in therapeutic procedures. Lately, by improvements in our perception of biological processes and immune system new classes of vaccines are emerged that grant us the opportunity of designing resolute constructs against desired antigens. In the current study, we used a variety of immunoinformatics tools to design a novel cancer vaccine against Preferentially Expressed Antigen of Melanoma (PRAME), which counts as a cancer testis antigen for various human cancers including BC. The PRAME up-regulation leads to strengthen BC stem cells maintenance, drug resistance, cell survival, adaptation, and apoptosis evading in cancerous cells.Methods and resultsThe PRAME co-expressed genes were mined and validated through BC RNA-sequencing of TCGA data. The immunodominant T-cell predicted epitopes were fused and engineered to form the vaccine. The safety, allergenicity, and immunogenic capabilities of the vaccine were confirmed by promising immunoinformatics tools. The vaccine’s structure was verified to be hydrophilic in most areas through Kyte and Doolittle hydrophobicity plotting. The interactions between the designed vaccine and immune receptors of TLR4 and IL1R were confirmed by protein-protein docking after modeling its tertiary structure. Finally, codon optimization and in silico cloning were performed to guarantee better in-vivo results.ConclusionIn conclusion, concerning in silico assessments’ results in this study, the designed vaccine can potentially boost immune responses against PRAME, therefore may decrease BC development and metastasis. According to the mined PRAME co-expressed genes and their functional annotation, cell cycle regulation is the prime mechanism opted by this construct and its adjacent regulatory genes along boosting immune reactions.     

HIV-1嵌合抗原的纯化及免疫原性分析

为获得高效的HIV诊断试剂,选定HIV-1的外膜蛋白env中469-511aa,538-674aa和700-734aa3处包含较多抗原位点的区域作为免疫抗原,用PCR的方法从HIV-1全基因扩增编码这3处片段的基因序列,将它们克隆到原核表达载体中,利用大肠杆菌表达系统表达嵌合蛋白.结果发现,3段嵌合基因能在大肠杆菌BL21(Star)中表达,通过Ni-sepharose4B金属Ni螯合层析柱分离纯化目的产物,酶联免疫检测结果表明,纯化抗原有较强的抗原特异性.