APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY
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2021
·Vol. 193
·期 11
·3753-3764
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IF 2.926
Chen Xiaochun,Huang Xiaoquan,Tang Yiwen,Zhang Lei
Nuclease P1 (NP1) can hydrolyze nucleic acids into four 5′-mononucleotides, which are widely used in the pharmaceutical and food industries. In this paper, an aqueous two-phase system (ATPS) was developed to purify NP1 from Penicillium citrinum . Polyethylene glycol (PEG) and nucleotides salts were studied to form ATPSs, among which PEG3000/disodium guanosine monophosphate (GMPNa 2 ) was researched, including the phase composition and pH. Using 14% (w/w) PEG3000 and 20% (w/w) GMPNa 2 ATPS at pH 5.0, the best recovery and purification factor, 82.4% and 3.59, were obtained. The recovery of NP1 was 98.3% by the separation of ultrafiltration from the PEG-rich phase. The recycling use of GMPNa 2 was also studied, and 95.1% of GMPNa 2 in the salt-rich phase was obtained with the addition of ethanol as the solvent. These results showed that the ATPS was effective for purification of NP1.
研究领域:
生物化学
·
工业微生物学
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COLLOIDS AND SURFACES B-BIOINTERFACES
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2016
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IF 3.902
Wei Zhuang,Linjiao He,Jiahua Zhu,Jianwei Zheng,Xiaojing Liu,Yihui Dong,Jinglan Wu,Jingwei Zhou,Yong Chen,Hanjie Ying
The use of graphene oxide (GO) nanosheets for functional enzyme support has attracted intensive interest owing to their unique planar structure and intriguing physical and chemical properties. However, the detailed effects of the interface properties of GO and its functionalized derivatives on active biomolecules are not well understood. We immobilize nuclease P 1 , a common industrial nucleic acid production enzyme, on pristine and amino poly(ethylene glycol) (PEG-NH 2 ) modified GO nanosheets with interface property heterogeneity using two approaches, physical adsorption and chemical crosslinking. It is demonstrated that nuclease P 1 could be stable immobilized on the surface of pristine GO by physical adsorption and on the edge of modified GO nanosheets by chemical crosslinking. The resultant loading capacity of nuclease P 1 on pristine GO is as high as 6.45 mg/mg as a consequence of strong electrostatic and hydrophobic interactions between the enzyme and carrier. However, it is determined that the acid resistance, thermal stability, reusability and degradation efficiency of the immobilized enzyme on PEG-NH 2 -modified GO are obviously improved compared to those of the enzyme immobilized on pristine GO. The enhanced catalytic behavior demonstrates that GO and its derivatives have great potential in efficient biocatalytic systems.
研究领域:
生物化学
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纳米生物学
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酶工程
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JOURNAL OF MOLECULAR CATALYSIS B-ENZYMATIC
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2014
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IF 2.745
Bingbing Li,Yong Chen,Zhi Cao,Huanqing Niu,Dong Liu,Ying He,Xiaochun Chen,Jinglan Wu,Jingjing Xie,Wei Zhuang,Hanjie Ying
The reversible immobilization of crude nuclease P 1 fermented by Penicllium citrinum and used without further purification was performed via adsorption on a weak base anion resin activated by polyethylenimine (PEI). The immobilization conditions, including PEI concentration, the amount of support, the immobilization time, and the reusability of the PEI-activated resin were investigated. The results have shown that the PEI-activated resin has the capability of selectively adsorbing nuclease P 1 . Subsequently, the functional properties of the immobilized nuclease P 1 were studied and compared to those of the free enzyme. The apparent K m value for immobilized nuclease P 1 on the activated resin (15.31 g L −1 ) was about 4.41-fold higher than that of the free enzyme (3.47 g L −1 ), and the apparent V max value of the immobilized enzyme (530 U g −1 ) was about 3.9-fold less than that of the free enzyme (2082 U mL −1 ). The optimum temperature was observed to be 70 °C, 15 °C higher than that of the free enzyme. The optimum pH was the same for both free and immobilized nuclease P 1 (pH 5.0). The apparent activation energies ( E a ) of the free and immobilized nuclease P 1 were 163.09 kJ mol −1 and 156.32 kJ mol −1 , respectively, implying that the catalytic efficiency of the immobilized enzyme was restricted by mass-transfer rather than kinetic limitations.
研究领域:
生物化学
·
酶工程
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JOURNAL OF NANOBIOTECHNOLOGY
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2026
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IF 15
Yuan Yin,Panyang Gu,Hanyu Jiang,Yumei Yang,Shujun Wang,Fei Yuan,Wenrui Zhong,Miao Chen,Meichun Deng
The widespread use of plastic products has led to a serious environmental problem, with nanoplastics ubiquitously contaminating the environment and sustaining human exposure, yet the impacts of nanoplastics on human health remain poorly understood. In this study, based on preliminary epidemiological investigations, we found that abnormal pain perception exists in populations chronically exposed to manufacturing environments that mainly produce polystyrene plastics. Further mechanistic studies demonstrated that high-dose polystyrene nanoparticles (PS NPs) induce pain hypersensitivity and elucidated their molecular underpinnings. Upon high-dose PS NPs exposure, microglia in the spinal dorsal horn internalized a fraction of the PS NPs, which were subsequently found to bind to mitogen-activated-protein-kinases (MAPK) pathway components (ERK, JNK, and p38). Molecular dynamics simulations further suggested that this binding could induce conformational alterations in the MAPK components, potentially enhancing the flexibility of their phosphorylation sites (Thr-X-Tyr) and thereby facilitating activation by upstream kinases. As a canonical inflammatory and pain-associated pathway, MAPK activation elevates neuroinflammatory cascades in the spinal dorsal horn, driving neuronal hyperexcitability and, consequently, pain hypersensitivity. Notably, the PS NPs-induced hypersensitivity was reversed by microglial depletion (PLX5622) and inhibition of the MAPK pathway. Collectively, our findings delineate PS NPs-triggered sensory pathophysiology and establish a proof-of-concept mechanistic nexus between environmental pollutants and aberrant somatosensation.
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