The interaction between phosphoryl transferase and submitochondrial particles

1968 ◽  
Vol 46 (7) ◽  
pp. 677-683 ◽  
Author(s):  
Robert E. Beyer
Keyword(s):  
Adenine Nucleotide ◽  
Major Determinant ◽  
Phosphoryl Group ◽  
Antimycin A ◽  
Submitochondrial Particles ◽  
Phosphorylated Form ◽  
Mitochondrial Transfer ◽  
Probable Role ◽  
Phosphoryl Groups

The interaction between purified phosphoryl transferase and submitochondrial particles has been studied. In the presence of submitochondrial particles the transferase is phosphorylated and the phosphorylated form of the transferase is dephosphorylated. Both of these interactions require that the particle be actively carrying out oxidation of succinate or NADH. Both antimycin A and oligomycin suppress the phosphorylation and dephosphorylation reactions. The uncoupler p-trifluoromethoxy-carbonylcyanide phenylhydrazone prevents the particle-mediated phosphorylation of the transferase but stimulates the dephosphorylation of the phosphorylated transferase to a slight extent. The concentration of bound adenine nucleotide in the particles appears to be a major determinant of the rate of phosphorylation of the transferase, and this dependence is consistent with the fact that the transfer of a phosphoryl group from the phosphorylated transferase to ADP proceeds rapidly and spontaneously. The probable role of the transferase in the mitochondrial transfer of phosphoryl groups from endogenous ATP to exogenous ADP is evaluated.

scholarly journals NADH- and NADPH-dependent lipid peroxidation in bovine heart submitochondrial particles. Dependence on the rate of electron flow in the respiratory chain and an antioxidant role of ubiquinol

1980 ◽  
Vol 192 (3) ◽  
pp. 853-860 ◽  
Author(s):  
R Takayanagi ◽  
K Takeshige ◽  
S Minakami
Keyword(s):  
Lipid Peroxidation ◽  
Respiratory Chain ◽  
Electron Flow ◽  
Antimycin A ◽  
Submitochondrial Particles ◽  
Bovine Heart ◽  
Malondialdehyde Formation ◽  
Low Rate ◽  
Liquid Peroxidation

Malondialdehyde formations by bovine heart submitochondrial particles supported by NADH or NADPH in the presence of ADP and FeCl3 was studied. The NADH-dependent reaction was maximal at very low rate of electron input from NADH to the respiratory chain and it decreased when the rate became high. The reaction was stimulated by rotenone and inhibited by antimycin A when the input was fast, whereas it was not affected by the inhibitors when the input was slow. The input rate of the electrons from NADPH was also so low that the reaction supported by NADPH was not affected by the inhibitors. Most of the endogenous ubiquinone in the particles treated with antimycin A was reduced by NADH even in the presence of ADP-Fe3+ chelate, but uniquinone was not reduced by NADPH when ADP-Fe3+ was present. Succinate strongly inhibited both NADH- and NADPH-dependent lipid peroxidation. The inhibition was abolished when uniquinone was removed from the particles, and it appeared again when uniquinone was reincorporated into the particles. Reduced uniquinone-2 also inhibited the peroxidation, but duroquinol, which reduces cytochrome b without reducing endogenous uniquinone, did not. Thus the malondialdehyde formation appeared to be inversely related to the extent of the reduction of endogenous uniquinone. These observations suggest that both NADH- and NADPH-dependent liquid-peroxidation reactions are closely related to the respiratory chain and that the peroxidation is controlled by the concentration of reduced ubiquinone.

A Probable Role of Eosinophilia, IgE and Complement in Bullous Pemphigoid Patients

1975 ◽  
Vol 37 (4) ◽  
pp. 532-540 ◽  
Author(s):  
Zenro IKEZAWA ◽  
Yo KAMEDA ◽  
Mitsuaki UCHIYAMA ◽  
Hiroshi NAKAJIMA ◽  
Toru BABA
Keyword(s):  
Bullous Pemphigoid ◽  
Probable Role

scholarly journals TOM20-mediated transfer of Bcl2 from ER to MAM and mitochondria upon induction of apoptosis

2021 ◽  
Vol 12 (2) ◽  
Author(s):  
Lisenn Lalier ◽  
Vincent Mignard ◽  
Marie-Pierre Joalland ◽  
Didier Lanoé ◽  
Pierre-François Cartron ◽  
...  
Keyword(s):  
Protein Import ◽  
Glioma Cells ◽  
Mitochondrial Outer Membrane ◽  
Mitochondrial Localization ◽  
Antiapoptotic Protein ◽  
Mitochondrial Transfer ◽  
Small Domain ◽  
Induction Of Apoptosis ◽  
And Function

AbstractIn this work, we have explored the subcellular localization of Bcl2, a major antiapoptotic protein. In U251 glioma cells, we found that Bcl2 is localized mainly in the ER and is translocated to MAM and mitochondria upon induction of apoptosis; this mitochondrial transfer was not restricted to the demonstrator cell line, even if cell-specific modulations exist. We found that the Bcl2/mitochondria interaction is controlled by TOM20, a protein that belongs to the protein import machinery of the mitochondrial outer membrane. The expression of a small domain of interaction of TOM20 with Bcl2 potentiates its anti-apoptotic properties, which suggests that the Bcl2–TOM20 interaction is proapoptotic. The role of MAM and TOM20 in Bcl2 apoptotic mitochondrial localization and function has been confirmed in a yeast model in which the ER–mitochondria encounter structure (ERMES) complex (required for MAM stability in yeast) has been disrupted. Bcl2–TOM20 interaction is thus an additional player in the control of apoptosis.

scholarly journals Probable role of Brain Natriuretic Peptide (BNP) in lung hypertension secondary to scleroderma

2013 ◽  
pp. 23-25
Author(s):  
P. Faggioli ◽  
S. Finazzi ◽  
E. Vicenzi ◽  
L. Giani ◽  
M. Rondena ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Progressive Systemic Sclerosis ◽  
New Drugs ◽  
Positivity Ratio ◽  
Probable Role ◽  
Biochemical Observation ◽  
And Gender ◽  
Roche Diagnostics ◽  
Worse Prognosis

BACKGROUND Scleroderma, when complicated with pulmonary hypertension (PHT), presents a worse prognosis; recently treatment with new drugs seems to offer good perspectives, especially in early diagnosis and treatment. The standard approach for diagnosing PHT consists in measurement of the pulmonary artery pressure (PAP) by means of echodoppler. AIM OF INVESTIGATION Aim of this work is evaluating the significance of the NT-proBNP parameter, matched to echodoppler, in diagnosing scleroderma PHT. MATERIALS AND METHODS Sixty (60) patients, who came to observation for progressive systemic sclerosis underwent echodoppler in order to measure the PAP (normal values up to 30 mmHg). NT-proBNP was determined on serum sample using ECLIA method by Modular E170 (Roche Diagnostics); manufacturer reference values for age and gender were used. Forty-three (43) patients underwent a further NT-proBNP sampling 5 days later in order to assess parameter stability. RESULTS PHT and non- PHT patients showed statistically different (p < 0,001) medians (126 vs 69 pg/ml). No pathologic values of NT-proBNP were measured in the group with PAP < 30 mmHg, while 27% of cases who had PAP between 30 and 40 showed pathologic concentrations. The positivity ratio increases to 57% in patients showing PAP > 40 mmHg. No relevant correlation (r = 0,2) was found between PAP and NT-proBNP. Mean average between the two sampling groups was 31%. CONCLUSIONS In scleroderma patients, combination of NT-proBNP and PAP seems to improve the diagnosis of pulmonary hypertension, especially in presence of borderline pulmonary pressure values. We therefore propose the biochemical observation of NT-proBNP when PAP is > 30 mmHg and in monitoring the evolution of the pathology.

scholarly journals The role of glutamine oxidation and the purine nucleotide cycle for adaptation of tumour energetics to the transition from the anaerobic to the aerobic state

1988 ◽  
Vol 252 (2) ◽  
pp. 381-386 ◽  
Author(s):  
Z Kovacević ◽  
D Jerance ◽  
O Brkljac
Keyword(s):  
Adenine Nucleotide ◽  
The Other ◽  
Purine Nucleotide ◽  
Purine Nucleotide Cycle ◽  
Adenine Nucleotide Pool

It is proposed that the purine nucleotide cycle and glutamine oxidation play a key role in the adaptation of tumour energetics to the transition from the anaerobic to the aerobic state. In support of this proposal, it was found that glutamine and inosine markedly increase total adenylates in the presence of oxygen, whereas the addition of hadacidin abolishes this effect. Transition of the cells from the anaerobic to the aerobic state, and vice versa, in the presence of glutamine plus inosine revealed that there are two components of the adenine nucleotide pool, one which is stable and the other which is variable and responds to the aerobic-anaerobic transition. This part of the pool undergoes degradation or resynthesis owing to activation of the enzymes of the purine nucleotide cycle. Resynthesis of the pool is accompanied by substantial net utilization of aspartate, which is produced by glutamine oxidation. This is supported by the experiments in which the cells were alternately incubated with nitrogen or oxygen, demonstrating that hadacidin significantly decreased utilization of aspartate and regeneration of ATP owing to inhibition of adenylosuccinate synthase.

scholarly journals A kinetic analysis of the changes in fluorescence on the interaction of 8-anilinonaphthalene-l-sulphonate with submitochondrial particles

1976 ◽  
Vol 158 (2) ◽  
pp. 295-305 ◽  
Author(s):  
N Gains ◽  
A P Dawson
Keyword(s):  
Kinetic Analysis ◽  
Mitochondrial Membrane ◽  
Antimycin A ◽  
Submitochondrial Particles ◽  
Submitochondrial Particle ◽  
Fluorescence Change

A comparison of the fluorescence change on the addition of 8-anilinonaphthalene-1-sulphonate to succinate-energized submitochondrial particles with that on the addition of succinate to submitochondrial particles incubated with 8-anilinonaphthalene-1-sulphonate shows that these changes in fluorescence may be explained solely in terms of 8-anilinonaphthalene-1-sulphonate binding. This comparison does not support the proposal of an 8-anilinonaphthalene-1-sulphonate-monitored change in the conformation of submitochondrial-particle membranes [Brocklehurst, Freedman, Hancock & Radda (1970) Biochem. J.116, 721-731]. The biphasic nature of the decrease in fluorescence, which was found to follow the addition of uncoupler to submitochondrial particles incubated with ATP or succinate, or of antimycin A to submitochondrial particles incubated with succinate, does not support the existence of ‘aplectic’ and ‘symplectic’ states of the mitochondrial membrane [Barrett-Bee & Radda (1972) Biochim, Biophys. Acta 267, 211-215].

scholarly journals Spinal Tolerance and Dependence: Some Observations on the Role of SpinalN-Methyl-D-Aspartate Receptors and Phosphorylation in the Loss of Opioid Analgesic Responses

2000 ◽  
Vol 5 (1) ◽  
pp. 33-39
Author(s):  
Tony L Yaksh ◽  
Xiao-Ying Hua
Keyword(s):  
Nmda Receptor ◽  
Opioid Analgesic ◽  
Dose Effect ◽  
Concurrent Treatment ◽  
Analgesic Effects ◽  
Delta Opioids ◽  
Probable Role ◽  
Pkc Isozymes ◽  
The Right

The continuous delivery of opiates can lead to a reduction in analgesic effects. In humans, as in other animals, some component of this change in sensitivity seems likely to have a strong pharmacodynamic component. Such loss of effect, deemed to be tolerance in the present article, can be readily demonstrated in animals with repeated bolus and continuous intrathecal infusion of mu and delta opioids and alpha-2 adrenergic agonists. Research has shown that this loss of effect can be diminished by concurrent treatment withN-methyl-D-aspartate (NMDA) receptor antagonists and by the suppression of the activity of spinal protein kinase C (PKC). This suggests in part the probable role of PKC-mediated phosphorylation in the right shift in the dose-effect curves observed with continuous opiate or adrenergic exposure. Importantly, this right shift is seen to occur in parallel with an increase in the phosphorylating activity in the dorsal horn and in the expression of several PKC isozymes. The target of this phosphorylation is not certain. Phosphorylation of the NMDA receptor enhances its functionality, while phosphorylation of the opioid receptor or associated channels seems to diminish their activity or to enhance internalization. While the focus is on several specific components, the accumulating data emphasize the biological complexity of these changes in spinal drug reactivity.

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