TALANTA
·
2019
·
IF 4.916
Jia-yuan Li,Xing-yu Long,Dong Sheng,Hong-zhen Lian
The iron oxide nanoparticles (Fe 3 O 4 ) were prepared by organic molecule-assisted method in aqueous solution. The facile synthetic process of Fe 3 O 4 nanoparticles was conducted only by mixing FeCl 2 and 2-methylimidazole (2-MIM) without any additives. A possible growth mechanism of the Fe 3 O 4 nanocrystals was proposed for this mild reaction. Then, the Fe 3 O 4 nanoparticles were anchored onto graphene oxide (GO) sheets in water by ultrasound-assisted method, forming an affinity probe with strong biocompatibility. Due to the hydroxy and carboxylic groups of GO sheets, Fe 3 O 4 /GO probe exhibits excellent performance for enriching low-abundance hydrophilic peptides, while the Fe 3 O 4 nanoparticles endure the probe with specific affinity to phosphopeptides. The analytical protocol was developed for sequential enrichment of low-abundance peptides and phosphopeptides by the affinity probe. It exhibited the sequence coverage of 26% for capture of 17 low-abundance peptides from bovine serum albumin (BSA), as well as the selectivity of 1:1:100 for phosphopeptides from α-/β-casein/BSA, and low detectable concentration of 2.5 fmol and probe reusability of 5 times for capture of phosphopeptides from α-/β-casein. Consequently, the prepared Fe 3 O 4 /GO material possesses excellent feature as multifunctional affinity probe for low-abundance peptides including phosphopeptides from complex biological matrices detected by matrix-assisted laser desorption ionization time-of-flight mass spectrometry.
研究领域:
生物化学
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分析化学
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材料科学
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DOI
PubMed
高影响因子
ANALYTICAL CHEMISTRY
·
2024
·
IF 6.7
Hang Ao,Wencheng Xiao,Wenrui Hu,Jie Wu,Huangxian Ju
This work designed a DNA conformation-regulated hemin switch for rapid chemiluminescent (CL) detection of a monoclonal antibodies. This switch was performed with an affinity probe and an inhibition probe, which were conveniently prepared by hybridizing hemin-labeled DNA1 with KHL peptide-labeled DNA2 and binding biotin-labeled DNA3 to streptavidin, respectively. In the absence of the target antibody, streptavidin-DNA3 could hybridize with hemin-DNA1/KHL-DNA2 to release KHL-DNA2, which led to the loss of hemin activity due to the affinity hindrance of streptavidin-DNA3. After the KHL peptide was recognized by the target antibody, the strand replacement hybridization could be inhibited by the bound antibody, which retained the high catalytic activity of hemin overhung on the antibody-bound affinity probe for a CL reaction, leading to a “signal-on” process for CL antibody detection. Using a KHL-specific antibody, anti-proprotein convertase subtilisin/kexin type 9 antibody (PCSK9-Ab), as a target model and common L012–1,2,4-triazole–H2O2 CL system, the designed switch showed a detection range of 10 ng mL–1 to 1 μg mL–1 with a detection limit of 4.16 ng mL–1 (56.2 pM) and a short analytical time of 6.5 min. The proposed quick method could simply be used for lab-on-chip CL detection of PCSK9-Ab in situ-secreted from PCSK9-6E3 hybridoma cells, which showed an accuracy of 90.2% compared with the statistical results from general fluorescence imaging, providing a potential technique for screening specific hybridoma cells.
研究领域:
生物化学
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分析化学
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生物技术
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分子生物学
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DOI
PubMed
高影响因子
Journal of Pharmaceutical Analysis
·
2024
·
IF 6.1
Yang Xu,Shujing Lv,Xiang Li,Chuanjia Zhai,Yulian Shi,Xuejiao Li,Zhiyang Feng,Gan Luo,Ying Wang,Xiaoyan Gao
Sennoside A (SA), a typical prodrug, exerts its laxative effect only after its transformation into rheinanthrone catalyzed by gut microbial hydrolases and reductases. Hydrolases have been identified, but reductases remain unknown. By linking a photoreactive group to the SA scaffold, we synthesized a photoaffinity probe to covalently label SA reductases and identified SA reductases using activity-based protein profiling. From lysates of an active strain, Bifidobacterium pseudocatenulatum ( B . pseudocatenulatum ), 397 proteins were enriched and subsequently identified using mass spectrometry. Among these proteins, chromate reductase/nicotinamide adenine dinucleotide phosphate (NADPH)-dependent flavin mononucleotide (FMN) reductase/oxygen-insensitive NADPH nitroreductase (nfrA) was identified as a potent SA reductase through further bioinformatic analysis and Uniprot database screening. We also determined that recombinant nfrA could reduce SA. Our study contributes to further illuminating mechanisms of SA transformation to rheinanthrone and simultaneously offers an effective method to identify gut bacterial reductases.
研究领域:
微生物学
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药理学
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蛋白质组学
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PubMed
高影响因子
MICROCHIMICA ACTA
·
2021
·Vol. 188
·期 10
·1-10
·
IF 5.833
Wang Baichun,Liu Jianmu,Yan Yinghua,Ding Chuan-Fan,Tang Keqi
A novel type of boric acid–functionalized magnetic covalent organic framework (mCOF) with polyethyleneimine (PEI) as a linker (denoted as mCOF@PEI@B(OH) 2 ) has been prepared through a post-synthesis strategy, which points out an achievable path for the construction of boronic acid–functionalized COFs. Based on the boric acid chemistry, the obtained core-shell structured mCOF@PEI@B(OH) 2 can selectively isolate glycopeptides through the modified boronic acid groups. The mCOF@PEI@B(OH) 2 exhibits excellent performance with good reusability (ten cycles), low detection limit (0.5 fmol·μL −1 ), size-exclusion effect, and relatively high loading capacity (80 μg·mg −1 ), recovery yield (94.9 ± 2.8%), and selectivity (HRP digests:BSA digests = 1:500). Detection is done by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). In addition, 37 endogenous glycopeptides are captured from human saliva with mCOF@PEI@B(OH) 2 , providing effective proofs for its capability to capture low-abundance glycopeptides from actual biological samples. Graphical abstract
研究领域:
材料科学
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分析化学
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生物化学
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质谱分析
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DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）