In Vivo Assembly of a Genetically Encoded Artificial Metalloenzyme for Hydrogen Production

2021 ◽  
Author(s):  
Kassandra J. Naughton ◽  
Regina E. Treviño ◽  
Peter J. Moore ◽  
Ashlee E. Wertz ◽  
J. Alex Dickson ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Artificial Metalloenzyme

scholarly journals Non-invasive continuous real-time in vivo analysis of microbial hydrogen production shows adaptation to fermentable carbohydrates in mice

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
José M. S. Fernández-Calleja ◽  
Prokopis Konstanti ◽  
Hans J. M. Swarts ◽  
Lianne M. S. Bouwman ◽  
Vicenta Garcia-Campayo ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Real Time ◽  
Non Invasive ◽  
In Vivo Analysis ◽  
Fermentable Carbohydrates

scholarly journals Re-routing photosynthetic energy for continuous hydrogen production in vivo

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Oren Ben-Zvi ◽  
Eyal Dafni ◽  
Yael Feldman ◽  
Iftach Yacoby
Keyword(s):  
Hydrogen Production ◽  
Electron Flow ◽  
Reducing Power ◽  
Full Potential ◽  
Oxygen Production ◽  
Sustainable Resources ◽  
Production Of Hydrogen ◽  
Enzyme Superoxide Dismutase

Abstract Background Hydrogen is considered a promising energy vector that can be produced from sustainable resources such as sunlight and water. In green algae, such as Chlamydomonas reinhardtii, photoproduction of hydrogen is catalyzed by the enzyme [FeFe]-hydrogenase (HydA). Although highly efficient, this process is transitory and thought to serve as a release valve for excess reducing power. Up to date, prolonged production of hydrogen was achieved by the deprivation of either nutrients or light, thus, hindering the full potential of photosynthetic hydrogen production. Previously we showed that the enzyme superoxide dismutase (SOD) can enhance HydA activity in vitro, specifically when tied together to a fusion protein. Results In this work, we explored the in vivo hydrogen production phenotype of HydA–SOD fusion. We found a sustained hydrogen production, which is dependent on linear electron flow, although other pathways feed it as well. In addition, other characteristics such as slower growth and oxygen production were also observed in Hyd–SOD-expressing algae. Conclusions The Hyd–SOD fusion manages to outcompete the Calvin–Benson cycle, allowing sustained hydrogen production for up to 14 days in non-limiting conditions.

Hydrogen Evolution Catalyzed by Hydrogenase in Cultures of Cyanobacteria

1981 ◽  
Vol 36 (1-2) ◽  
pp. 87-92 ◽  
Author(s):  
Patrick C. Hallenbeck ◽  
Leon V. Kochian ◽  
John R. Benemann
Keyword(s):  
Hydrogen Production ◽  
Hydrogen Evolution ◽  
High Frequency ◽  
Nitrogenase Activity ◽  
Inhibitory Effect ◽  
Hydrogenase Activity ◽  
Oxygen Inhibition ◽  
Oxygen Sensitive

Abstract Cultures of Anabaena cylindrica, grown on media containing 5 mᴍ NH4Cl (which represses heterocyst formation), evolved hydrogen after a period of dark incubation under an argon atmosphere. This hydrogen production was not due to nitrogenase activity, which was nearly undetectable, but was due to a hydrogenase. Cultures grown on media with tungsten substituted for molybdenum had a high frequency of heterocysts (15%) and inactive nitrogenase after nitrogen starvation. The hydrogenase activity of these cultures was three-fold greater than the activity of non-heterocystous cultures. The effects of oxygen inhibition on hydrogen evolution by hetero-cystous cultures suggest that two pools of hydrogenase activity exist - an oxygen sensitive hydrogen evolution in vegetative cells and a relatively oxygen-resistent hydrogen evolution in heterocysts. In either case, inhibition by oxygen was reversible. Light had an inhibitory effect on net hydrogen evolution. Hydrogen production in vitro was much higher than in vivo, indicating that in vivo hydrogenase activity is limited by endogenous reductant supply.

Cyanobacterial in vivo solar hydrogen production using a photosystem I–hydrogenase (PsaD-HoxYH) fusion complex

Nature Energy ◽  
2020 ◽  
Vol 5 (6) ◽  
pp. 458-467 ◽  
Author(s):  
Jens Appel ◽  
Vanessa Hueren ◽  
Marko Boehm ◽  
Kirstin Gutekunst
Keyword(s):  
Hydrogen Production ◽  
Photosystem I ◽  
Solar Hydrogen ◽  
Solar Hydrogen Production

scholarly journals Disrupting tumor onset and growth via selective cell tagging (SeCT) therapy

2021 ◽  
Vol 7 (17) ◽  
pp. eabg4038
Author(s):  
Kenward Vong ◽  
Tsuyoshi Tahara ◽  
Sayaka Urano ◽  
Igor Nasibullin ◽  
Kazuki Tsubokura ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Therapeutic Response ◽  
Protein Labeling ◽  
Significant Delay ◽  
Delay Reduction ◽  
Tumor Onset ◽  
Early Tumor ◽  
Further Development ◽  
Artificial Metalloenzyme

This study presents the early framework of selective cell tagging (SeCT) therapy, which is the concept of preferentially labeling specific cells in vivo with chemical moieties that can elicit a therapeutic response. Using glycosylated artificial metalloenzyme (GArM)–based protein labeling, this study reports two separate functional strategies. In one approach, early tumor onset can be suppressed by tagging cancer cells in living mice with an integrin-blocking cyclic–Arg-Gly-Asp (cRGD) moiety, thereby disrupting cell adhesion onto the extracellular matrix. In another approach, tumor growth in mice can be reduced by tagging with a cytotoxic doxorubicin moiety. Subsequent cell death occurs following internalization and drug release. Overall, experiments have shown that mouse populations receiving the mixture of SeCT labeling reagents exhibited a significant delay/reduction in tumor onset and growth compared with controls. Highlighting its adaptability, this work represents a foundational step for further development of SeCT therapy and its potential therapeutic applications.

scholarly journals Dinitrogenase-Driven Photobiological Hydrogen Production Combats Oxidative Stress in Cyanothece sp. Strain ATCC 51142

2016 ◽  
Vol 82 (24) ◽  
pp. 7227-7235 ◽  
Author(s):  
Natalie C. Sadler ◽  
Hans C. Bernstein ◽  
Matthew R. Melnicki ◽  
Moiz A. Charania ◽  
Eric A. Hill ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Production ◽  
System Level ◽  
Oxygenic Photosynthesis ◽  
Hydrogenase Activity ◽  
Enzyme Complex ◽  
Strain Atcc ◽  
Content Type ◽  
Thiol Redox

ABSTRACTPhotobiologically synthesized hydrogen (H2) gas is carbon neutral to produce and clean to combust, making it an ideal biofuel.Cyanothecesp. strain ATCC 51142 is a cyanobacterium capable of performing simultaneous oxygenic photosynthesis and H2production, a highly perplexing phenomenon because H2evolving enzymes are O2sensitive. We employed a system-levelin vivochemoproteomic profiling approach to explore the cellular dynamics of protein thiol redox and how thiol redox mediates the function of the dinitrogenase NifHDK, an enzyme complex capable of aerobic hydrogenase activity. We found that NifHDK responds to intracellular redox conditions and may act as an emergency electron valve to prevent harmful reactive oxygen species formation in concert with other cell strategies for maintaining redox homeostasis. These results provide new insight into cellular redox dynamics useful for advancing photolytic bioenergy technology and reveal a new understanding for the biological function of NifHDK.IMPORTANCEHere, we demonstrate that high levels of hydrogen synthesis can be induced as a protection mechanism against oxidative stress via the dinitrogenase enzyme complex inCyanothecesp. strain ATCC 51142. This is a previously unknown feature of cyanobacterial dinitrogenase, and we anticipate that it may represent a strategy to exploit cyanobacteria for efficient and scalable hydrogen production. We utilized a chemoproteomic approach to capture thein situdynamics of reductant partitioning within the cell, revealing proteins and reactive thiols that may be involved in redox sensing and signaling. Additionally, this method is widely applicable across biological systems to achieve a greater understanding of how cells navigate their environment and how redox chemistry can be utilized to alter metabolism and achieve homeostasis.

A Simple Method of Measuring Breath Hydrogen in Carbohydrate Malabsorption by End-Expiratory Sampling

1976 ◽  
Vol 50 (3) ◽  
pp. 237-240 ◽  
Author(s):  
G. Metz ◽  
M. A. Gassull ◽  
A. R. Leeds ◽  
L. M. Blendis ◽  
D. J. A. Jenkins
Keyword(s):  
Gas Chromatography ◽  
Hydrogen Production ◽  
Hydrogen Concentration ◽  
Coefficient Of Variation ◽  
Breath Hydrogen ◽  
Simple Method ◽  
Alveolar Air ◽  
Carbohydrate Malabsorption

1. A simple method is described for measuring the hydrogen concentration in alveolar air by end-expiratory sampling, by using a modified Haldane—Priestley tube and gas chromatography. Hydrogen was generated in vivo by ingestion of the non-absorbable sugar lactulose. 2. Alveolar hydrogen concentration showed a highly significant correlation with hydrogen production measured either by a rebreathing technique or by a total collection procedure. 3. The coefficient of variation of the end-expiratory method, assessed by comparing sixty-one paired results, was 11·6%. The coefficient of variation in ten measurements in one subject at 1 min intervals was 17·6%.

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