scholarly journals Origin and Control of Chemoselectivity in Cytochrome c Catalyzed Carbene Transfer into Si–H and N–H bonds

2021 ◽  
Author(s):  
Marc Garcia-Borràs ◽  
S. B. Jennifer Kan ◽  
Russell D. Lewis ◽  
Allison Tang ◽  
Gonzalo Jimenez-Osés ◽  
...  
Keyword(s):  
Cytochrome C ◽  
Carbene Transfer ◽  
And Control

STUDIES ON THERMOGENESIS IN COLD-ACCLIMATED BIRDS

1963 ◽  
Vol 41 (1) ◽  
pp. 2215-2220 ◽  
Author(s):  
R. R. J. Chaffee ◽  
W. W. Mayhew ◽  
M. Drebin ◽  
Y. Cassuto
Keyword(s):  
Oxygen Consumption ◽  
Cytochrome C ◽  
Liver Enzyme ◽  
Intravenous Injection ◽  
Pyridine Nucleotide ◽  
Small Rodents ◽  
Organ Weights ◽  
Enzyme Systems ◽  
And Control ◽  
Shivering Thermogenesis

Effects on oxygen consumption of continuous intravenous injection of various doses of L-noradrenaline were measured in anesthetized chickens acclimated to 1 °C for 3 months, and in controls. No effects were produced in either and it is concluded that noradrenaline is not a calorigenic mediator in cold-acclimated chickens. Liver succinoxidase and liver microsomal pyridine nucleotide-cytochrome c reductases of cold-acclimated and control sparrows were assayed, and there were no cold-induced differences. Since small cold-acclimated mammals show elevation of these liver enzyme systems, the findings indicate that the chemical basis of non-shivering thermogenesis (if this phenomenon is present at all) may involve different mechanisms in birds and mammals. Organ weights were measured, and it was found that in the sparrow, as in small rodents, the kidney and heart become enlarged in response to cold, perhaps indicating a convergent adaptation in these two diverse homoeotherms. Changes in the thickness and changes in color of the pectoral muscles which were observed in the cold-acclimated sparrows are discussed in relation to their possible roles in shivering thermogenesis.

scholarly journals The Effect of Follicular-fluid Exposure of Endometriosis Cyst Patients toward the Levels of Bcl-2 and Cytochrome-C in Mice Oocyte

2020 ◽  
Vol 8 (A) ◽  
pp. 567-570
Author(s):  
Ida Bagus Putra Adnyana ◽  
I Made Jawi ◽  
Ketut Suwiyoga ◽  
I Made Bakta ◽  
I Nyoman Mantik Astawa ◽  
...  
Keyword(s):  
Cytochrome C ◽  
Follicular Fluid ◽  
Clinical Manifestations ◽  
World Health ◽  
Control Group ◽  
Mitochondrial Apoptosis ◽  
Control Group Design ◽  
Significance Level ◽  
Treatment Groups ◽  
And Control

BACKGROUND: Endometriosis cysts adversely affect a woman’s quality of life, which causes pain and reduces fertility. The World Health Organization found that the incidence of endometriosis with infertility clinical manifestations is around 10%. AIM: The purpose of this study is to determine the presence of mice oocytes mitochondrial apoptosis exposed with endometriosis cysts follicular fluid through Bcl-2 and cytochrome C analysis. METHODS: This study was a randomized post-test only control group design conducted at Sanglah Hospital, Bali Royal Hospital in Denpasar, and the Medical Faculty Udayana University from June 2018 to April 2019. A total of 120 mice oocytes were distributed randomly into three groups, i.e., treatment Groups 1 and 2 that added by 15% endometriosis cysts follicular fluid and control group. Bcl-2 and Cytochrome C analyzed with ELISA Technique. Comparability was tested with one-way ANOVA with a significance level of p < 0.05. RESULTS: Eighteen mice oocyte replicates were normally distributed and homogeneous. The Bcl-2 levels in the treatment Groups 1, and 2 and control were 627.83 ± 146.42, 634.50 ± 140.62, and 678.83 ± 152.71, respectively; p = 0.838 (not significantly different). Cytochrome C levels in the treatment Groups 1, and 2, and control, respectively, were 3147.75 ± 228.50, 3104.45 ± 211.29, and 2738.28 ± 227.45; p = 0.021 (significantly different). CONCLUSION: The effect of endometriosis cysts follicular fluid exposure on mitochondrial apoptosis is proven through Cytochrome C, whereas Bcl-2 is not proven.

scholarly journals Origin and Control of Chemoselectivity in Cytochrome c-Catalyzed Carbene Transfer into Si–H and N–H bonds

2021 ◽  
Author(s):  
Marc Garcia-Borràs ◽  
S. B. Jennifer Kan ◽  
Russell D. Lewis ◽  
Allison Tang ◽  
Gonzalo Jiménez-Osés ◽  
...  
Keyword(s):  
Cytochrome C ◽  
Bond Formation ◽  
Conformational Dynamics ◽  
Active Species ◽  
Chemical Transformations ◽  
Carbene Insertion ◽  
Biological World ◽  
Selective Chemical ◽  
And Control ◽  
Loop Conformation

<div><div><div><p>A cytochrome c heme protein was recently engineered to catalyze the formation of carbon–silicon bonds via carbene insertion into Si–H bonds, a reaction that was not previously known to be catalyzed by a protein. High chemoselectivity towards C–Si bond formation over competing C–N bond formation was achieved, although this trait was not screened for during directed evolution. Using computational and experimental tools, we now establish that activity and chemoselectivity are modulated by conformational dynamics of a protein loop that covers the substrate access to the iron-carbene active species. Mutagenesis of residues computationally predicted to control the loop conformation altered the protein’s chemoselectivity from preferred silylation to preferred amination of a substrate containing both N–H and Si–H functionalities. We demonstrate that information on protein structure and conformational dynamics, combined with knowledge of mechanism, leads to understanding of how non-natural and selective chemical transformations can be introduced into the biological world.</p></div></div></div>

STUDIES ON THERMOGENESIS IN COLD-ACCLIMATED BIRDS

1963 ◽  
Vol 41 (11) ◽  
pp. 2215-2220 ◽  
Author(s):  
R. R. J. Chaffee ◽  
W. W. Mayhew ◽  
M. Drebin ◽  
Y. Cassuto
Keyword(s):  
Oxygen Consumption ◽  
Cytochrome C ◽  
Liver Enzyme ◽  
Intravenous Injection ◽  
Pyridine Nucleotide ◽  
Small Rodents ◽  
Organ Weights ◽  
Enzyme Systems ◽  
And Control ◽  
Shivering Thermogenesis

Effects on oxygen consumption of continuous intravenous injection of various doses of L-noradrenaline were measured in anesthetized chickens acclimated to 1 °C for 3 months, and in controls. No effects were produced in either and it is concluded that noradrenaline is not a calorigenic mediator in cold-acclimated chickens. Liver succinoxidase and liver microsomal pyridine nucleotide-cytochrome c reductases of cold-acclimated and control sparrows were assayed, and there were no cold-induced differences. Since small cold-acclimated mammals show elevation of these liver enzyme systems, the findings indicate that the chemical basis of non-shivering thermogenesis (if this phenomenon is present at all) may involve different mechanisms in birds and mammals. Organ weights were measured, and it was found that in the sparrow, as in small rodents, the kidney and heart become enlarged in response to cold, perhaps indicating a convergent adaptation in these two diverse homoeotherms. Changes in the thickness and changes in color of the pectoral muscles which were observed in the cold-acclimated sparrows are discussed in relation to their possible roles in shivering thermogenesis.

scholarly journals mTORC1 is required for expression of LRPPRC and cytochrome-c oxidase but not HIF-1α in Leigh syndrome French Canadian type patient fibroblasts

2019 ◽  
Vol 317 (1) ◽  
pp. C58-C67
Author(s):  
Yvette Mukaneza ◽  
Aaron Cohen ◽  
Marie-Ève Rivard ◽  
Jessica Tardif ◽  
Sonia Deschênes ◽  
...  
Keyword(s):  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Pyruvate Dehydrogenase ◽  
Leigh Syndrome ◽  
Metabolic Reprogramming ◽  
Pyruvate Dehydrogenase Kinase ◽  
French Canadian ◽  
Atp Levels ◽  
Ribosomal S6 Kinase ◽  
And Control

Leigh syndrome French Canadian type (LSFC) is a mitochondrial disease caused by mutations in the leucine-rich pentatricopeptide repeat-containing (LRPPRC) gene leading to a reduction of cytochrome- c oxidase (COX) expression reaching 50% in skin fibroblasts. We have shown that under basal conditions, LSFC and control cells display similar ATP levels. We hypothesized that this occurs through upregulation of mechanistic target of rapamycin (mTOR)-mediated metabolic reprogramming. Our results showed that compared with controls, LSFC cells exhibited an upregulation of the mTOR complex 1 (mTORC1)/p70 ribosomal S6 kinase pathway and higher levels of hypoxia-inducible factor 1α (HIF-1α) and its downstream target pyruvate dehydrogenase kinase 1 (PDHK1), a regulator of mitochondrial pyruvate dehydrogenase 1 (PDH1). Consistent with these signaling alterations, LSFC cells displayed a 40–61% increase in [U-13C6]glucose contribution to pyruvate, lactate, and alanine formation, as well as higher levels of the phosphorylated and inactive form of PDH1-α. Interestingly, inhibition of mTOR with rapamycin did not alter HIF-1α or PDHK1 protein levels in LSFC fibroblasts. However, this treatment increased PDH1-α phosphorylation in control and LSFC cells and reduced ATP levels in control cells. Rapamycin also decreased LRPPRC expression by 41 and 11% in LSFC and control cells, respectively, and selectively reduced COX subunit IV expression in LSFC fibroblasts. Taken together, our data demonstrate the importance of mTORC1, independent of the HIF-1α/PDHK1 axis, in maintaining LRPPRC and COX expression in LSFC cells.

scholarly journals Differential responses to endurance training in subsarcolemmal and intermyofibrillar mitochondria

1998 ◽  
Vol 85 (4) ◽  
pp. 1279-1284 ◽  
Author(s):  
Michael E. Bizeau ◽  
Wayne T. Willis ◽  
Jeffrey R. Hazel
Keyword(s):  
Cytochrome C ◽  
Endurance Training ◽  
Treadmill Running ◽  
Control Groups ◽  
Mitochondrial Oxygen Consumption ◽  
Cytochrome C Reductase ◽  
Hindlimb Muscles ◽  
M 10 ◽  
Succinate Cytochrome C Reductase ◽  
And Control

To examine the effect of endurance training (6 wk of treadmill running) on regional mitochondrial adaptations within skeletal muscle, subsarcolemmal (SS) and intermyofibrillar (IMF) mitochondria were isolated from trained and control rat hindlimb muscles. Mitochondrial oxygen consumption (V˙o 2) was measured polarographically by using the following substrates: 1 mM pyruvate + 1 mM malate (P+M), 10 mM 2-oxoglutarate, 45 μM palmitoyl-dl-carnitine + 1 mM malate, and 10 mM glutamate. Spectrophotometric assays of cytochrome- c reductase and NAD-specific isocitrate dehydrogenase (IDH) activity were also performed. Maximal (state III) and resting (state IV)V˙o 2 were lower in SS than in IMF mitochondria in both trained and control groups. In SS mitochondria, training elicited significant 36 and 20% increases in state III V˙o 2 with P+M and glutamate, respectively. In IMF mitochondria, training resulted in a smaller (20%), yet significant, increase in state IIIV˙o 2 with P+M as a substrate, whereas state IIIV˙o 2 increased 33 and 27% with 2-oxoglutarate and palmitoyl-dl-carnitine + malate, respectively. Within groups, cytochrome- c reductase and IDH activities were lower in SS when compared with IMF mitochondria. Training increased succinate-cytochrome- c reductase in both SS (30%) and IMF mitochondria (28%). IDH activity increased 32% in the trained IMF but remained unchanged in SS mitochondria. We conclude that endurance training promotes substantial changes in protein stoichiometry and composition of both SS and IMF mitochondria.

scholarly journals Origin and Control of Chemoselectivity in Cytochrome c-Catalyzed Carbene Transfer into Si–H and N–H bonds

2021 ◽  
Author(s):  
Marc Garcia-Borràs ◽  
S. B. Jennifer Kan ◽  
Russell D. Lewis ◽  
Allison Tang ◽  
Gonzalo Jiménez-Osés ◽  
...  
Keyword(s):  
Cytochrome C ◽  
Bond Formation ◽  
Conformational Dynamics ◽  
Active Species ◽  
Chemical Transformations ◽  
Carbene Insertion ◽  
Biological World ◽  
Selective Chemical ◽  
And Control ◽  
Loop Conformation

<div><div><div><p>A cytochrome c heme protein was recently engineered to catalyze the formation of carbon–silicon bonds via carbene insertion into Si–H bonds, a reaction that was not previously known to be catalyzed by a protein. High chemoselectivity towards C–Si bond formation over competing C–N bond formation was achieved, although this trait was not screened for during directed evolution. Using computational and experimental tools, we now establish that activity and chemoselectivity are modulated by conformational dynamics of a protein loop that covers the substrate access to the iron-carbene active species. Mutagenesis of residues computationally predicted to control the loop conformation altered the protein’s chemoselectivity from preferred silylation to preferred amination of a substrate containing both N–H and Si–H functionalities. We demonstrate that information on protein structure and conformational dynamics, combined with knowledge of mechanism, leads to understanding of how non-natural and selective chemical transformations can be introduced into the biological world.</p></div></div></div>

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