Browse
Submit Data
Databases
API
Help

Dataset Information

11 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

A study of GDP binding to purified thermogenin protein from brown adipose tissue.

ABSTRACT: 1. The binding of GDP to purified thermogenin protein was studied by using fluorescence spectroscopy and equilibrium dialysis. 2. GDP binding to thermogenin diminished fluorescence emission in a concentration-dependent manner that exhibited saturation. 3. Kd values for binding of nucleoside di- and tri-phosphates were lower than those for nucleoside monophosphates. 4. The GDP-induced fluorescence quenching was decreased by increasing pH, but the apparent Kd was unaltered by pH changes. 5. Equilibrium dialysis showed a Kd change from 3 to 6 microM when the pH was increased from 6.6 to 8.5. 6. The apparent pK of the fluorescence changes induced by pH (8.3) was identical with the apparent pK of the GDP-binding response. 7. The data are consistent with the existence of protonated and non-protonated forms of thermogenin protein that both bind GDP.

SUBMITTER: French RR

PROVIDER: S-EPMC1149014 | biostudies-other | 1988 Apr

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Similar Datasets

Effect of corticotropin on brown adipose tissue mitochondrial GDP binding in obese rats.

Project description:Corticotropin stimulated brown adipose tissue mitochondrial GDP binding of young obese rats to the levels seen in lean rats. This effect was attenuated by chronic increases in corticosterone. The stimulatory response to corticotropin was absent from lean rats unless endogenous secretion of corticosterone was prevented.

| S-EPMC1144289 | biostudies-other

GDP binding to brown-adipose-tissue mitochondria of mice treated chronically with corticosterone.

Project description:Cytochrome oxidase activity and mitochondrial GDP binding were decreased in brown adipose tissue of mice treated chronically with corticosterone. These changes occurred both in corticosterone-treated mice fed ad libitum and in treated mice pair-fed to control animals. Although the dietary stimulation of brown-adipose-tissue thermogenesis was suppressed by corticosterone, the acute response to cold was not affected.

| S-EPMC1152236 | biostudies-other

The effect of adrenalectomy on GDP binding to brown-adipose-tissue mitochondria of obese rat.

Project description:GDP binding to brown-adipose-tissue mitochondria of young obese Zucker rats (fa/fa) was significantly lower than in lean control rats, as a result of a decrease in the number of binding sites. Adrenalectomy of fa/fa rats restored GDP binding to control values. Corticosterone replacement suppressed GDP binding in adrenalectomized obese rats.

| S-EPMC1154036 | biostudies-other

Cold exposure induces different uncoupling-protein thermogenin masking/unmasking processes in brown adipose tissue depending on mitochondrial subtypes.

Project description:The effect of cold exposure on thermogenic parameters such as mitochondrial protein content, GDP-binding and uncoupling protein (UCP) levels in different mitochondrial fractions from rat brown adipose tissue has been investigated. Rats were exposed from 12 h to 5 days at 4 degrees C, and three mitochondrial fractions were isolated by differential centrifugation: the M1 fraction (1000 g), the M3 fraction (3000 g) and the M15 fraction (15,000 g). Cytochrome c oxidase activity as an index of mitochondrial mass showed an increase during cold exposure. During the first 24 h of cold exposure UCP was incorporated specifically into the M3 and M15 mitochondrial fractions, and thereafter UCP appeared in the heaviest M1 fraction. However, specific GDP binding was increased during the first 24 h in the same way in all subpopulations, and this increase continued up to 72 h of cold exposure. Results suggest that different molecular events are involved during acute and chronic adaptation to cold: during the first 24 h of cold acclimatization, thermogenic activity is increased by an unmasking process of the UCP binding sites in the M1 mitochondrial fraction as UCP levels were constant and GDP binding increased, but in the M3 and M15 fraction the increase in thermogenic activity was completely due to an increase in GDP binding induced by a specific incorporation of UCP targeted to these mitochondria. Thus thermogenic parameters change in a different way in the brown-fat mitochondrial subpopulations during cold acclimatization.

| S-EPMC1138185 | biostudies-other

Functional atrophy of brown adipose tissue during lactation in mice. Effects of lactation and weaning on mitochondrial GDP binding and uncoupling protein.

Project description:The thermogenic activity and capacity of brown adipose tissue were determined in mice during lactation and after weaning. There was a marked fall during lactation in the mitochondrial content of the tissue, and in GDP binding and the specific mitochondrial concentration of uncoupling protein. The lactation-induced functional atrophy of brown adipose tissue was fully reversible after weaning; mitochondrial content and the mitochondrial concentration of uncoupling protein were both restored, although GDP binding was not normalized.

| S-EPMC1148530 | biostudies-other

Regulation of GDP binding and uncoupling-protein concentration in brown-adipose-tissue mitochondria. The effects of cold-acclimation, warm-reacclimation and noradrenaline.

Project description:We have used a specific immunoassay for uncoupling protein and [3H]GDP binding to study the acute and chronic responses of brown-adipose-tissue (BAT) mitochondria of warm-acclimated rats to housing at 4 degrees C and cold-acclimated rats to housing at 27 degrees C. These studies have shown the following. (1) In the cold-exposed rat the increase in mitochondrial uncoupling-protein concentration parallels the increase in GDP binding from 1 day to 5 days, but that acutely (initial 4 h) the increase in GDP binding is not associated with any change in uncoupling-protein concentration. 2. In the cold-acclimated rat rehoused at 27 degrees C, GDP binding fell by over 50% in the first 2 days, without any change in uncoupling-protein concentrations. 3. Noradrenaline acutely (30 min) increased BAT mitochondrial GDP binding of lean and obese Zucker rats, without any change in uncoupling-protein concentrations. 4. The increases in GDP binding in cold-exposed rats were associated with increases in the rate of swelling of mitochondria in the presence of valinomycin and potassium acetate. The evidence supports the hypothesis that the acute response of the rat to changes in environmental temperature are associated with unmasking or remasking of uncoupling protein, whereas chronically changes in uncoupling-protein concentration predominate.

| S-EPMC1148724 | biostudies-other

Evidence for unmasking of rat brown-adipose-tissue mitochondrial GDP-binding sites in response to acute cold exposure. Effects of washing with albumin on GDP binding.

Project description:Rats, previously acclimated to 29 degrees C, were moved into the cold (4 degrees C) for 2 h. Scatchard analysis of GDP binding to the brown-adipose-tissue mitochondria of these animals showed a 2.3-fold increase in the number of high-affinity sites and a 1.5-fold increase in the number of low-affinity sites compared with binding in animals maintained at 29 degrees C. Immunochemical determination showed no increase in the amount of mitochondrial uncoupling protein during this period. This strongly suggests an unmasking of existing GDP-binding sites before a detectable increase in synthesis of uncoupling protein can occur. Washing with albumin increased the number of GDP-binding sites of brown-adipose-tissue mitochondria from both warm-housed and cold-exposed animals to the same extent. This indicates that the effects of washing with albumin and cold exposure are independent and additive.

| S-EPMC1153094 | biostudies-other

Brown adipose tissue whitening leads to brown adipocyte death and adipose tissue inflammation.

Project description:In mammals, white adipose tissue (WAT) stores and releases lipids, whereas brown adipose tissue (BAT) oxidizes lipids to fuel thermogenesis. In obese individuals, WAT undergoes profound changes; it expands, becomes dysfunctional, and develops a low-grade inflammatory state. Importantly, BAT content and activity decline in obese subjects, mainly as a result of the conversion of brown adipocytes to white-like unilocular cells. Here, we show that BAT "whitening" is induced by multiple factors, including high ambient temperature, leptin receptor deficiency, β-adrenergic signaling impairment, and lipase deficiency, each of which is capable of inducing macrophage infiltration, brown adipocyte death, and crown-like structure (CLS) formation. Brown-to-white conversion and increased CLS formation were most marked in BAT from adipose triglyceride lipase (Atgl)-deficient mice, where, according to transmission electron microscopy, whitened brown adipocytes contained enlarged endoplasmic reticulum, cholesterol crystals, and some degenerating mitochondria, and were surrounded by an increased number of collagen fibrils. Gene expression analysis showed that BAT whitening in Atgl-deficient mice was associated to a strong inflammatory response and NLRP3 inflammasome activation. Altogether, the present findings suggest that converted enlarged brown adipocytes are highly prone to death, which, by promoting inflammation in whitened BAT, may contribute to the typical inflammatory state seen in obesity.

| S-EPMC5928436 | biostudies-literature

GDP binding to brown-adipose-tissue mitochondria of diabetic--obese (db/db) mice. Decreased binding in both the obese and pre-obese states.

Project description:GDP binding to brown-adipose-tissue mitochondria from adult diabetic--obese (db/db) mice was significantly less than with lean siblings. Binding was also decreased in the mutant mice before obesity had begun to develop. Decreased GDP binding was found to result from a decrease in the number of binding sites.

| S-EPMC1162842 | biostudies-other

Acute effects of a beta-adrenoceptor agonist (BRL 26830A) on rat brown-adipose-tissue mitochondria. Increased GDP binding and GDP-sensitive proton conductance without changes in the concentration of uncoupling protein.

Project description:GDP binding, proton conductance and the specific concentration of uncoupling protein were measured in brown-adipose-tissue mitochondria of rats treated acutely with the novel beta-agonist, BRL 26830A. At 1 h after dosing with BRL 26830A, mitochondrial GDP binding was increased more than 2-fold. The increase in binding resulted from an increase in the number of binding sites. An iterative analysis of Scatchard binding data suggested that there is only one high-affinity GDP-binding site (Kd 0.3 microM) in brown-adipose-tissue mitochondria. The acute increase in GDP binding produced by treatment with BRL 26830A occurred without any alteration in the specific mitochondrial concentration of uncoupling protein, as determined by radioimmunoassay. Treatment with the beta-agonist did, however, lead to a small increase in the GDP-sensitive component of mitochondrial proton conductance. These results indicate that GDP-binding sites on uncoupling protein can be rapidly unmasked after treatment with a brown-fat-specific beta-agonist, and that the increase in binding reflects an increase in the activity of the mitochondrial proton-conductance pathway.

| S-EPMC1148771 | biostudies-other

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data