MACROMOLECULAR CHEMISTRY AND PHYSICS
·
2021
·Vol. 222
·期 13
·2100070
·
IF 2.527
Hongyang Wang,Shuai Lan,Yu Zhang,Lu Zhang,Dandan Jia,Weiguo Zhang,Chun Liu,Lei Cao,Dongjun Wang
For the unusual phenomenon of nontraditional intrinsic luminescence, a systematic fluorescence study is conducted in the phase transformation from solution through hydrogel to solid states. In this process, significant differences are found in fluorescence intensity, peak position, lifetime, and excitation-dependent emission. In particular, the samples in the hydrogel state show two fluorescent peaks at 480 and 516 nm, respectively, while only one fluorescent peak is detected in the cases of solution (at 516 nm) or solid (at around 450 nm). More interestingly, the longer wavelength peak presents excitation-dependent fluorescence, and the shorter one is excitation-independent. These unique fluorescent observations can be ascribed to the fact that the aggregates of amine groups act as the actual fluorescent centers, which are quite sensitive to their surrounding microenvironments. Based on these results, some simulation tests of sensors and intelligent hydrogels in response to water are also studied.
研究领域:
材料科学
·
光学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
Foods
·
2024
·Vol. 13
·期 6
·851
·
IF 4.7
Kun Xie,Feng Yang,Xian’e Ren,Yongchun Huang,Fengyan Wei
Effects of different ionic strengths (0.2, 0.4, and 0.6 mol/L) and different hydrodynamic cavitation (HC) treatment times (0, 1, 2, 3, and 4 min) on the conformation and gel properties of tilapia myofibrillar proteins (TMP) were investigated. The results showed that the solubility of TMP was significantly enhanced (p< 0.05) with the increase in NaCl concentration, and the gel characteristics were significantly improved. After HC treatment of TMP, the average particle size was significantly reduced (p< 0.05) and solubility was significantly enhanced (p< 0.05) with the increase in treatment time, the internal hydrophobic groups and reactive sulfhydryl groups were exposed. The intrinsic fluorescence spectra showed the unfolding of the spatial tertiary structure of proteins, and the circular dichroism spectroscopy showed the significant reduction in the content of α-helix in the secondary structure of the proteins (p< 0.05). In addition, the WHC and gel strength of the TMP heat-induced gels were enhanced, which improved the microstructure of the gels, and scanning electron microscopy showed that the gel network of the TMP gels became denser and more homogeneous. Dynamic rheology results showed that HC treatment resulted in a significant increase in the final G’ and G” values of TMP. In conclusion, HC treatment was able to improve the physicochemical structure and gel properties of TMP at different ionic strengths. This study presents a novel processing technique for the quality maintenance aspect of salt-reduced surimi gel products.
研究领域:
食品科学
·
蛋白质化学
·
水生生物学
✓ 已验证
DOI
PubMed
高影响因子
Analytical Methods
·
2019
·Vol. 11
·期 9
·1248-1253
·
IF 2.378
Dehua Deng,Yuanqiang Hao,Ping Yang,Ning Xia,Wenxue Yu,Xiuhua Liu,Lin Liu
A general peptide substrate for the specific detection of proteases is linked with a quencher/fluorophore pair. However, labeling of the substrate with a quencher/fluorophore pair may increase the complexity for the synthesis of peptides and affect the approach of protease to the cleavage site. A peptide with a specific sequence has been shown to bind Cu2+ with high affinity. More intriguingly, Cu2+ exhibits a high inherent quenching ability towards the fluorophore by complexation with the sequence-specific peptide. Based on this fact, this work reports a general single-labeled peptide substrate for the detection of protease activity, screening of potential inhibitors and evaluation of cell apoptosis. The feasibility and applications of the method were demonstrated by assays of caspase-3 and β-secretase with a signal-on and a signal-off format, respectively.
研究领域:
生物化学
·
分子生物学
·
分析化学
·
药物发现
✓ 已验证
DOI
高影响因子
FOOD HYDROCOLLOIDS
·
2022
·
IF 11.504
Kefan Ouyang,Hexiang Xie,Yufeng Wang,Meng Wai Woo,Qian Chen,Sixing Lai,Hua Xiong,Qiang Zhao
In this study, phosphoric acid was used to replace hydrochloric acid which is widely reported in the production of whey protein isolate fibrils (WPF). The pH, temperature, and protein concentration for the phosphoric acid-induced fibrillation were optimized (4% w/v, pH 2.5, 90 °C). Under this condition, the mean particle size and molecular weight decreased significantly while the ζ-potential increased slightly, it suggested that the fibrillation was accompanied by hydrolysis . WPF was already formed via intermolecular interactions at 6 h, which exhibited a semiflexible and unbranched filament of about 10 nm in diameter. A few single-filament flexible fibrils (about 5 nm in diameter) formed at 24 h. Thioflavin T analysis supported by Intrinsic fluorescence showed that the use of phosphoric acid accelerated the fibrillation. The ANS fluorescence and Second-derivative UV–vis spectra indicated the increase in surface hydrophobicity, peaking after 12 h of heating. Compared with the hydrochloric acid induced, WPF induced by phosphoric acid exhibited a shorter lag phase and maintained a more stable dispersion state with a nanoscale particle size. The great interfacial properties and proper aspect ratio (length/diameter) provided the contribution that WPF effectively absorbed at the oil-water interface. Moreover, the emulsion stability of the WPF improved with increasing salt concentration. The phosphoric acid-induced WPF had the best emulsion stability at pH 5.5 which was further enhanced by proper heating.
研究领域:
食品科学
·
蛋白质化学
·
胶体科学
·
乳液技术
✓ 已验证
DOI
高影响因子
FOOD HYDROCOLLOIDS
·
2022
·
IF 11.504
Zhenyu Yang,Lei Dai,Qingjie Sun,David Julian McClements,Xingfeng Xu
Previously, it has been shown that rice glutelin with a degree of hydrolysis of 2% (DH2) can form stable oil-in-water emulsions, but the stabilization mechanism has not yet been elucidated. In this study, the molecular, interfacial, and emulsifying properties of DH2 were investigated to better understand the structure-function relationships of this emulsifier. Peptides with relatively small (<5 kDa), medium (5–10 kDa), and large (>10 kDa) molecular weights were separated from DH2 by ultrafiltration . The large and medium peptides exhibited the highest surface hydrophobicity and intrinsic fluorescence intensity, respectively. Dynamic interfacial tension and quartz crystal microbalance with dissipation (QCM-D) analysis was utilized to characterize the interfacial properties. The large peptides exhibited a faster adsorption rate and a greater reduction in interfacial tension than the others. QCM-D indicated that the properties of the interfacial layers formed by the peptides were different during adsorption or desorption for all samples. The properties of the emulsions formed using the different peptides were characterized by confocal laser scanning microscopy, particle size, flocculation index, and coalescence index analysis. The storage stability of the emulsions increased as the molecular weight of the peptides used to coat the oil droplets increased, which may have been due to an increase in the steric repulsion caused by thicker interfacial layers. These results indicate that the large peptides in DH2 play the most important role in forming and stabilizing emulsions. This knowledge may be used to increase the utilization of hydrolyzed rice proteins as plant-based emulsifiers in foods and beverages.
研究领域:
食品科学
·
胶体科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL PHYSICS
·
2021
·
IF 2.348
Deying Meng,Huangmei Zhou,Jianhua Xu,Sanjun Zhang
Salicylic acid and its monohydroxy substituted derivatives are usually used as food additives . They can interact with bovine serum albumin (BSA) through π-π stacking, the monohydroxy substitutions can hinder the interactions through steric effects . In this paper, we systematically studied the interactions between BSA and salicylic acid and its monohydroxy substituted derivatives under simulative physiological conditions by diverse spectroscopic methods and molecular docking studies. The spectroscopic studies showed that the intrinsic fluorescence of BSA could be quenched by salicylic acid and its derivatives. The quenching mechanism is a combination of static and dynamic quenching. Furthermore, the molecular docking simulation revealed the binding sites (near the Trp-213 in the BSA) and the distance (2.1 nm, 2.9 nm, 2.0 nm, 2.7 nm and 3.3 nm, respectively) between ligand and protein, which is in good agreement with the calculated results of the energy transfer process . Our research may provide guidance for understanding the interactions between serum albumin and salicylic acid food additives.
研究领域:
药学化学
·
生物化学
·
分子生物学
✓ 已验证
产品关联
DOI
高影响因子
AQUACULTURE
·
2020
·
IF 3.225
Weiliang Guan,Wenqian Nong,Xiaobo Wei,Minqi Zhu,Linchun Mao
A novel strategy of water-free transportation (WFT) for live shrimp was recently developed. In this study, survival rate, hormone response, free radical content, oxidation in lipids and proteins, and flesh quality were evaluated after WFT. Meanwhile water transportation (WT) was employed as a reference for comparison. Results showed only 5.1% mortality after 10 h of WFT, while crustacean hyperglycemic hormone (CHH), reactive nitrogen species (RNS), free fatty acid content (FFA), peroxide value (PV), carbonyl concentration, intrinsic fluorescence intensity (IFI), and surface hydrophobicity significantly increased. Myosin heavy chain (MHC) and actin degradation were also detected after WFT. Although oxidation occurred in lipids and proteins, no significant changes in texture and water-holding capacity (WHC) were detected after WFT or WT ( p > 0.05). The 10 h of WFT showed little influence on flesh quality of shrimp even though lipids and proteins oxidation occurred during the mimicked water-free transportation.
研究领域:
水产养殖
·
食品科学
·
应激生理学
✓ 已验证
产品关联
DOI
高影响因子
ANALYTICAL CHEMISTRY
·
2022
·
IF 8.008
Shijie Dai,Wei Li,Ruimin Xu,Xin Wang,Qianjin Li,Menghua Dou,Jianlin Li
We have demonstrated the proof-of-concept of a label-free fluorescence quantitative detection platform based on gold nanoparticle (AuNP) enhancement intrinsic fluorescence of protein on the silica photonic crystal microsphere (SPCM) array. The label-free one-step competitive fluorescence immunoassay protocol has been proposed on the surface of the SPCM. Aflatoxin B1 (AFB1) as a model molecule was detected by the newly established method. AFB1-bovine serum albumin and monoclonal antibodies (Abs) of anti-AFB1 have been immobilized on the surfaces of SPCMs and AuNPs, respectively. AuNPs remarkably enhanced the intrinsic fluorescence of artificial antigens on the surface of the SPCM at near UV excitation. The simulation of electric field distribution showed that the maximum value of the near-field enhancement |E/E0| of the SPCM with AuNPs could reach 20. The label-free fluorescence enhancement effect comes from the synergistic effects of photonic crystal effect and AuNP plasmon effect. Such a label-free fluorescence detection method can provide a linear detection range from 0.1 to 10 ng/mL with a limit of detection of 0.025 ng/mL and good specificity for AFB1. The recovery rates in the spiked cereal samples were measured in the range of 84.07 ± 5.71%–101.02 ± 5.13%, which were consistent with that of the traditional enzyme linked immunosorbent assay method. The label-free detection platform displays great application potential in biology, medicine, agriculture, food industry, chemical industry, energy source, and environmental protection.
研究领域:
生物技术
·
分析化学
·
食品安全
·
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）