SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
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2024
·
IF 4.3
Zuoxu Chen,Soji Shimizu,Sheng Ji,Jianming Pan,Yue Wang,Ru Feng
A novel alkaline pH-responsive probe based on an asymmetric aza-BODIPY was synthesized in a one-pot Schiff base formation reaction. This pH-sensitive probe comprises an asymmetric aza-BODIPY as the luminescent core, with a benzothiazole moiety connected via an imine bond serving as the recognition site. The probe exhibits a turn-off fluorescence response upon exposure to alkaline pH (9.6–12.4), while a bathochromic band in the absorption emerges due to its extended π-conjugation system, accompanied by a visible colorimetric change from yellow to orange to red. Furthermore, the probe responds linearly in the highly alkaline region, with a p K a of 11.65. The recognition mechanism of the probe towards alkaline pH relies on the deprotonation of the imine group on the aza-BODIPY core, leading to an enhanced degree of π-electron conjugation. The quenched fluorescence intensity is attributed to the increased non-radiative decay of the deprotonated form of the probe. The probe demonstrates high reliability for practical applications due to its photostability and reversibility. This study provides new insights into the design of probes for detecting high alkaline pH levels.
研究领域:
分析化学
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生物化学
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产品关联
DOI
PubMed
高影响因子
FOOD HYDROCOLLOIDS
·
2021
·
IF 9.147
Junmeng Lu,Xinglian Xu,Xue Zhao
In the current study, the interfacial rheological properties of alkali pH-shifted MP under pH 11.0 → 7.0, pH 11.5 → 7.0 and pH 12.0 → 7.0 have been firstly investigated. The molecular weight and microstructure of myofibrillar protein (MP) treated by alkali pH-shifting were investigated by gel-permeation chromatography (GPC) and transmission electron microscopy (TEM). Results indicated a swollen, organized and aggregated structure of refolded MP. Overall, the molecular change in refolded MP led to faster protein adsorption towards the O/W interface, enhanced intermolecular interaction between adsorbed proteins and improved elasticity of interfacial film compared to native MP. After β-mercaptoethanol (β-ME) was added, the advantage of refolded MP in diffusion phase no more existed due to the disruption of aggregation and decreased molecular size, besides the penetration and rearrangement were interfered because the disruption of disulfide bond inhibited the formation of interfacial protein layers. With the protein concentration increasing, MP molecules crowding at O/W (oil in water) surface limited the development of a highly elastic network. As revealed by Tween 20 displacement, MP layers with higher interfacial elasticity were more resistant to displacement. Moreover, after displacement the coalescence stability of emulsion droplet was enhanced but the mechanical strength of interfacial MP layer was reduced. Altogether MP (0.04 or 0.2 mg/mL) treated by pH 11.0 → 7.0 exhibited the best adsorption performance and interfacial properties, which were important in stablizing emulsions. Thus, interfacial behavior regulation by alkali pH-shifting may be a applicable process for developing meat protein-based emulsions in food industry.
研究领域:
食品科学
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蛋白质化学
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胶体科学
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DOI
高影响因子
BIOTECHNOLOGY LETTERS
·
2017
·Vol. 39
·期 12
·1903-1910
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IF 1.73
Liu Ke,Zhou Youzhi,Zhang Jinsong,Chu Jianlin,Zhang Yewei,He Bingfang
Objective To isolate a thermostable pyrimidine nucleoside phosphorylase (PyNP) from mesophilic bacteria by gene mining. Results
Bb PyNP from Brevibacillus borstelensis LK01 was isolated by gene mining. Bb PyNP had a highest 60% identity with that of reported PyNPs. Bb PyNP could catalyze the phosphorolysis of thymidine, 2′-deoxyuridine, uridine and 5-methyuridine. Bb PyNP had good thermostability and retained 73% of its original activity after 2 h incubation at 50 °C. Bb PyNP had the highest activity at an optimum alkaline pH of 8.5. Bb PyNP was stable from pH 7 to 9.8. Under preliminary optimized conditions, the biosynthesis of various 5-halogenated pyrimidine nucleosides by Bb PyNP reached the yield of 61–84%. Conclusion An efficient approach was estimated in isolating thermostable PyNP from mesophilic bacteria.
研究领域:
生物化学
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酶学
·
生物技术
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产品关联
DOI
PubMed
高影响因子
Food Science and Human Wellness
·
2023
·
IF 7
Weijun Leng,Xiaoyun Wu,Xianghui Qi,Hongying Liu,Li Yuan,Ruichang Gao
In this study, a gene encoding serine protease ( PmSpr288 ) from cold-adapted bacterium, namely Planococcus maritimus XJ11, was cloned and overexpressed in Escherichia coli BL21 (DE3). Bioinformatics analysis revealed that PmSpr288 belongs to serine protease S8 superfamily with a classical catalytic triad comprised by the Asp49, His86 and Ser251. Moreover, PmSpr288 was found to be active over broad alkaline pH and low-moderate temperature, and exhibited wide range of protein substrate specificity. In addition, PmSpr288 was able to hydrolyze the meat proteins actin and myosin, and molecular docking results suggested that the crucial interaction between PmSpr288 and actin/myosin complexes was mainly occupied by hydrogen bonds. The muscle protein hydrolysates of silver carp prepared by PmSpr288 was shown to have antioxidant activity via DPPH radical scavenging assay, which presented an IC 50 valve of 1.309 mg/mL. In conclusion, these characteristics imply that PmSpr288 has potential biotechnological application prospect for the production of bioactive peptides.
研究领域:
微生物学
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生物化学
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生物技术
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食品科学
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产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2023
·Vol. 47
·期 22
·10849-10856
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IF 3.3
Hufeng Fang,Shan Xu,Jinhong Gong,Lidan Tang,Xiaomei He,Ying Lin,Hao Yang,Kun Yan,Dan Su,Yujing Leng
Metabolic alkalosis, the most common acid–base disorder, is related to significantly increased mortality in hospitalized patients. Hunting for pH sensors lying in the neutral to alkaline pH range still remains challenging and in demand. Herein, we engineered a colorimetric/fluorescent method for monitoring alkalic pH based on a phenylboronic acid-containing probe (DDPB). In this approach, the dicyanoisophorone group of DDPB acted as an optical signal moiety, while the boronic acid acted as the latent pH response site. It was exactly deciphered that the reversible pH monitoring principle is based on the deprotonation/protonation mechanism and intramolecular charge transfer (ICT) strategy via1H NMR and DFT calculations. This approach presented a pH-sensitive response over pH values ranging from 7.00 to 10.23 (pKa = 9.33) with excellent reversibility. We further explored its application in sensing pH on a paper substrate for visual and rapid detection. In addition, it was successfully applied to measure pH variations in HK-2 cells when the cells underwent alkalosis. This work extends the application of optical probes based on boronic acid under alkaline pH conditions, and provides a new strategy for the design of alkaline pH probes.
研究领域:
化学
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材料科学
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生物医学工程
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细胞生物学
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DOI
高影响因子
危险品化学品经营许可证（带存储）