Biomimetic Mineralization of Cytochrome c Improves the Catalytic Efficiency and Confers a Functional Multi-Enzyme Composite

The encapsulated enzyme system by metal-organic frameworks (MOFs) exhibits great potential in biofuel cells, pharmaceuticals, and biocatalysis. However, the catalytic efficiency and the enzymatic activity are severely hampered due to enzyme leaching and deficiency of storage stability. In this study, we immobilized cytochrome c (Cyt c) into dimethylimidazole-copper (Cu(Im)2) by biomimetic mineralization, and constructed a bioinorganic hybrid material, termed Cyt c@Cu(Im)2. Encapsulated Cyt c in Cu(Im)2 with a nanosheet structure exhibited significantly improved catalytic efficiency, enzymatic activity and kinetic performance. The catalytic efficiency (kcat/Km) for Cyt c@Cu(Im)2 was ~20-fold higher compared to that of free Cyt c. Moreover, the increased activity was not affected by long-term storage. Based on this system, we further constructed a multi-enzyme composite with glucose-oxidase (GOx), termed GOx-Cyt c@Cu(Im)2, which exhibited greatly improved enzymatic activity, stability, and excellent selectivity for the detection of low concentrations of glucose. This strategy may provide new insights into the design of enzymes with high activity and stability, as well as the construction of multi-enzyme systems.

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Is adipose tissue suitable for detection of (synthetic) cannabinoids? A comparative study analyzing antemortem and postmortem specimens following pulmonary administration of JWH-210, RCS-4, as well as ∆9-tetrahydrocannabinol to pigs

Archives of Toxicology ◽

10.1007/s00204-020-02843-x ◽

2020 ◽

Vol 94 (10) ◽

pp. 3421-3431

Author(s):

Nadine Schaefer ◽

Frederike Nordmeier ◽

Ann-Katrin Kröll ◽

Christina Körbel ◽

Matthias W. Laschke ◽

...

Keyword(s):

Adipose Tissue ◽

Synthetic Cannabinoids ◽

Standard Addition ◽

Storage Conditions ◽

Long Term Storage ◽

Low Concentrations ◽

Concentration Changes ◽

Term Storage ◽

Plateau Level

Abstract Examining fatal poisonings, chronic exposure may be reflected by the concentration in tissues known for long-term storage of drugs. Δ9-tetrahydrocannabinol (THC) persists in adipose tissue (AT), but sparse data on synthetic cannabinoids (SC) are available. Thus, a controlled pig study evaluating antemortem (AM) disposition and postmortem (PM) concentration changes of the SC 4-ethylnaphthalene-1-yl-(1-pentylindole-3-yl)methanone (JWH-210) and 2-(4-methoxyphenyl)-1-(1-pentyl-indole-3-yl)methanone (RCS-4) as well as THC in AT was performed. The drugs were administered pulmonarily (200 µg/kg body weight) to twelve pigs. Subcutaneous (s.c.) AT specimens were collected after 15 and 30 min and then hourly up to 8 h. At the end, pigs were sacrificed and s.c., perirenal, and dorsal AT specimens were collected. The carcasses were stored at room temperature (RT; n = 6) or 4 °C (n = 6) and specimens were collected after 24, 48, and 72 h. After homogenization in acetonitrile and standard addition, LC–MS/MS was performed. Maximum concentrations were reached 0.5–2 h after administration amounting to 21 ± 13 ng/g (JWH-210), 24 ± 13 ng/g (RCS-4), and 22 ± 20 ng/g (THC) and stayed at a plateau level. Regarding the metabolites, very low concentrations of N-hydroxypentyl-RCS-4 (HO-RCS-4) were detected from 0.5 to 8 h. PM concentrations of parent compounds did not change significantly (p > 0.05) over time under both storage conditions. Concentrations of HO-RCS-4 significantly (p < 0.05) increased in perirenal AT during storage at RT. These results suggest a rapid distribution and persistence in s.c. AT. Furthermore, AT might be resistant to PM redistribution of parent compounds. However, significant PM increases of metabolite concentrations might be considered in perirenal AT.

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Susceptibility of Japanese pears to low concentrations of ethylene during storage

Australian Journal of Experimental Agriculture ◽

10.1071/ea06186 ◽

2007 ◽

Vol 47 (12) ◽

pp. 1480 ◽

Cited By ~ 2

Author(s):

M. J. Szczerbanik ◽

K. J. Scott ◽

J. E. Paton ◽

D. J. Best

Keyword(s):

Carbon Dioxide ◽

Low Cost ◽

Pyrus Pyrifolia ◽

Green Colour ◽

Long Term Storage ◽

Low Concentrations ◽

Internal Browning ◽

Term Storage

The ‘Nijisseiki’ cultivar of Japanese pears (Pyrus pyrifolia) is also known as nashi in Australia. Nashi were exposed to levels of <0.005, 0.01, 0.1 and 1.0 µL/L of ethylene in air during 26 weeks storage at 0°C. Levels of ethylene as low as 0.01 µL/L increased chlorophyll loss and visual green colour. Increasing ethylene levels also increased softening and internal browning, although flesh spot decay was reduced in the presence of ethylene. While it would be worthwhile to remove ethylene during long-term storage of ‘Nijisseiki’ in air, another alternative, adding 2% carbon dioxide to the atmosphere, is suggested as a possible low cost means to overcome the ripening effect of ethylene.

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Preservation of Avian Cells at Sub-zero Temperatures

Australian Journal of Biological Sciences ◽

10.1071/bi9790475 ◽

1979 ◽

Vol 32 (5) ◽

pp. 475 ◽

Cited By ~ 3

Author(s):

N Ratnamohan ◽

PB Spradbrow

Keyword(s):

Dimethyl Sulfoxide ◽

Cryoprotective Agent ◽

Cryoprotective Agents ◽

Long Term Storage ◽

Low Concentrations ◽

Short And Long Term ◽

Term Storage

The cryoprotective agents dimethyl sulfoxide (DMSO), glycerol, polyvinylpyrrolidone (PVP) and dextran were evaluated for their ability to protect avian cells during storage at sub-zero temperatures. DMSO was the most effective cryoprotective agent for the short- and long-term storage of avian cells and glycerol was also effective when used at low concentrations. PVP and dextran did not protect avian cells during storage in our experiments. Primary chicken cells and avian cells at higher passage levels were successfully recovered after storage with DMSO for periods ranging from 4 to 12 months.

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Comparative Analysis of the Effect of Immersion of Porous Silicon in Aqueous Solutions of Li and Fe Salts on the Stability, Peak Position and Intensity of its Photoluminescence

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.386.75 ◽

2018 ◽

Vol 386 ◽

pp. 75-79

Author(s):

Nikolay G. Galkin ◽

Dmitrii Tkhyarbonovich Yan ◽

Konstantin N. Galkin ◽

Evgeniy Anatolievich Chusovitin ◽

Mikhail Victorovich Bozhenko

Keyword(s):

Porous Silicon ◽

Aqueous Solutions ◽

Blue Shift ◽

Peak Position ◽

Maximum Increase ◽

Long Term Storage ◽

Low Concentrations ◽

The Stability ◽

Term Storage

In the process of comparative studies of immersing layers of porous silicon (PS) in aqueous solutions of LiBr and Fe (NO3)3 with subsequent long-term storage up to 150 days, it is established that there exists: (1) the range of concentrations of LiBr (S/2 - S/4) and Fe (NO3)3 (0.2 M), which provide the maximum increase in the intensity of PL; (2) at low concentrations of both salts, a blue shift of the PL peaks and an increase in their intensity are observed during the long-term storage, which is associated with a decrease in the size of the NC in the PS and the influence of silicon bonds with lithium or iron ions; (3) full protection of the PS layer is observed in case of immersion in Fe (NO3)3 with a concentration of 0.7M - 0.8M.

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Long-term protein packaging in cholinium-based ionic liquids: improved catalytic activity and enhanced stability of cytochrome c against multiple stresses

Green Chemistry ◽

10.1039/c7gc02011b ◽

2017 ◽

Vol 19 (20) ◽

pp. 4900-4911 ◽

Cited By ~ 42

Author(s):

Meena Bisht ◽

Dibyendu Mondal ◽

Matheus M. Pereira ◽

Mara G. Freire ◽

P. Venkatesu ◽

...

Keyword(s):

Enzyme Activity ◽

Catalytic Activity ◽

Ionic Liquids ◽

Cytochrome C ◽

Multiple Stresses ◽

Improved Stability ◽

Cyt C ◽

Enhanced Stability

Cholinium-based ionic liquids are shown to be promising packaging media of Cyt c with >50 fold enhancement in the enzyme activity and improved stability against multiple stresses.

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A Study on the Combination of Enzyme Stabilizers and Low Temperatures in the Long-Term Storage of Glutamate Biosensor

Chemosensors ◽

10.3390/chemosensors9060129 ◽

2021 ◽

Vol 9 (6) ◽

pp. 129

Author(s):

Andrea Bacciu ◽

Paola Arrigo ◽

Rossana Migheli ◽

Alessandra T. Peana ◽

Gaia Rocchitta ◽

...

Keyword(s):

Enzymatic Activity ◽

Low Temperatures ◽

Triethylene Glycol ◽

Storage Conditions ◽

Low Temperature Storage ◽

Long Term Storage ◽

The Impact ◽

Term Storage

The importance of physiological glutamate has been widely demonstrated in cognitive and memory processes, as well as in neurotransmission. The involvement of physiological glutamate in several pathologies has also been established. Therefore, analytical devices for studying variations in physiological glutamate are of fundamental importance, particularly in preclinical studies. The necessary knowledge to develop and characterize biosensors for glutamate detection is often restricted to only a few research groups. However, many more groups have sought to implant such analytical devices to study the glutamatergic system in vivo. On this basis, a series of studies was undertaken to explore the medium-term storage of biosensors, thereby allowing their usage results to be differentiated from their construction and characterization processes to facilitate the wider diffusion and use of such sensors. Therefore, it has become vital to determine the best storage conditions to extend the life and functionality of these biosensors, especially due to the diachronic instability of the enzyme present on the surface. In the present study, we analyzed the impact of glycols, such as glycerol and triethylene glycol, as enzyme stabilizers coupled with long-term storage at low temperatures (−20 and −80 °C) on biosensor performance. The biosensors were observed for 5 months and evaluated for their enzymatic activity by measuring the VMAX(app) and KM(app). The analytical features were also evaluated in terms of the Linear Region Slope, which is one the most important parameters for indicating the efficiency and the sensitivity of biosensors. Interestingly, both glycols proved to be capable of increasing enzymatic activity and maintaining good biosensor efficiency over time. Moreover, the combination with low-temperature storage highlighted the different behaviors of the two glycols. In particular, glycerol was more effective in stabilizing the enzyme and maintaining analytical performance when the biosensors were stored at −20 °C. Instead, triethylene glycol performed the same function as glycerol but when the biosensors were stored at −80 °C.

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The Impact of Structural Defects on Iodine Adsorption in UiO-66

Chemistry ◽

10.3390/chemistry3020037 ◽

2021 ◽

Vol 3 (2) ◽

pp. 525-531

Author(s):

John Maddock ◽

Xinchen Kang ◽

Lifei Liu ◽

Buxing Han ◽

Sihai Yang ◽

...

Keyword(s):

Metal Organic Framework ◽

Nuclear Fission ◽

Structural Defects ◽

Gravimetric Analysis ◽

Long Term Storage ◽

Defect Sites ◽

Metal Organic ◽

The Impact ◽

And Storage

Radioactive I2 (iodine) produced as a by-product of nuclear fission poses a risk to public health if released into the environment, and it is thus vital to develop materials that can capture I2 vapour. Materials designed for the capture and storage of I2 must have a high uptake capacity and be stable for long-term storage due the long half-life of 129I. UiO-66 is a highly stable and readily tuneable metal-organic framework (MOF) into which defect sites can be introduced. Here, a defective form of UiO-66 (UiO-66-FA) was synthesised and the presence of missing cluster moieties confirmed using confocal fluorescence microscopy and gas sorption measurements. The uptake of I2 vapour in UiO-66-FA was measured using thermal gravimetric analysis coupled mass spectrometry (TGA-MS) to be 2.25 g g−1, almost twice that (1.17 g g−1) of the pristine UiO-66. This study will inspire the design of new efficient I2 stores based upon MOFs incorporating structural defects.

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Bioanalysis of doxorubicin aglycone metabolites in human plasma samples–implications for doxorubicin drug monitoring

Scientific Reports ◽

10.1038/s41598-020-75662-w ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Christian Siebel ◽

Claudia Lanvers-Kaminsky ◽

Gudrun Würthwein ◽

Georg Hempel ◽

Joachim Boos

Keyword(s):

Point Of Care ◽

Storage Period ◽

Drug Level ◽

Hplc Method ◽

Clinical Samples ◽

Long Term Storage ◽

Low Concentrations ◽

Degradation Pattern ◽

One Year

Abstract The widespread clinical use of the cytostatic doxorubicin together with the induction of chronic cardiomyopathy necessitates the conduct of further pharmacokinetic trials. Novel analytical technologies suitable for point-of-care applications can facilitate drug level analyses but might be prone to interferences from structurally similar compounds. Besides the alcohol metabolite doxorubicinol, aglycone metabolites of doxorubicin might affect its determination in plasma. To evaluate their analytical relevance, a validated HPLC method for the quantification of doxorubicin, doxorubicinol and four aglycones was used. The degradation pattern of doxorubicin in plasma under long-term storage was analysed with respect to the formation of aglycone products. In addition, overall 50 clinical samples obtained within the EPOC-MS-001-Doxo trial were analysed. Substantial degradation of doxorubicin in plasma occurred within a storage period of one year, but this did not lead to the formation of aglycones. In clinical samples, 7-deoxydoxorubicinolone was the major aglycone detectable in 35/50 samples and a concentration range of 1.0–12.7 µg L−1. If at all, the other aglycones were only determined in very low concentrations. Therefore, analytical interferences from aglycones seem to be unlikely with the exception of 7-deoxydoxorubicinolone whose concentration accounted for up to 65% of the doxorubicin concentration in the clinical samples analysed.

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Glucose oxidase and Au nanocluster co-encapsulated metal–organic frameworks as a sensitive colorimetric sensor for glucose based on a cascade reaction

New Journal of Chemistry ◽

10.1039/c9nj06339k ◽

2020 ◽

Vol 44 (31) ◽

pp. 13344-13349

Author(s):

Jingtian Chi ◽

Manli Guo ◽

Chi Zhang ◽

Yuanhong Zhang ◽

Shiyun Ai ◽

...

Keyword(s):

Glucose Oxidase ◽

Glucose Sensor ◽

Storage Stability ◽

Metal Organic Frameworks ◽

High Sensitivity ◽

Long Term Storage ◽

Sensitivity And Selectivity ◽

Metal Organic ◽

Term Storage

The GOx & AuNCs@ZIF-8 composite was simply obtained as a colorimetric glucose sensor with high sensitivity and selectivity and long-term storage stability.

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Biomimetic mineralization of nitrile hydratase into a mesoporous cobalt-based metal–organic framework for efficient biocatalysis

Nanoscale ◽

10.1039/c9nr06470b ◽

2020 ◽

Vol 12 (2) ◽

pp. 967-972 ◽

Cited By ~ 5

Author(s):

Xiaolin Pei ◽

Yifeng Wu ◽

Jiapao Wang ◽

Zhiji Chen ◽

Wen Liu ◽

...

Keyword(s):

Thermal Stability ◽

Nitrile Hydratase ◽

Metal Organic Framework ◽

Catalytic Efficiency ◽

Biomimetic Mineralization ◽

Metal Organic ◽

Organic Framework

Recombinant cobalt-type NHase was encapsulated into ZIF-67 to improve its thermal stability and catalytic efficiency by a biomimetic mineralization strategy.

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