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PubMed1998

The mechanism of detergent solubilization of liposomes and protein-containing membranes.

The present study explores intermediate stages in detergent solubilization of liposomes and Ca2+-ATPase membranes by sodium dodecyl sulfate (SDS) and medium-sized ( approximately C12) nonionic detergents. In all cases detergent partitioning in the membranes precedes cooperative binding and solubilization, which is facilitated by exposure to detergent micelles. Nonionic detergents predominantly interact with the lipid component of Ca2+-ATPase membranes below the CMC (critical micellar concentration), whereas SDS extracts Ca2+-ATPase before solubilization of lipid. At the transition to cooperative binding, n-dodecyl octaethylene glycol monoether (C12E8), Triton X-100, and dodecyldimethylamine oxide induce fusion of small unilamellar liposomes to larger vesicles before solubilization. Solubilization of Ca2+-ATPase membranes is accompanied by membrane fragmentation and aggregation rather than vesicle fusion. Detergents with strongly hydrophilic heads (SDS and beta-D-dodecylmaltoside) only very slowly solubilize liposomal membranes and do not cause liposome fusion. These properties are correlated with a slow bilayer flip-flop. Our data suggest that detergent solubilization proceeds by a combination of 1) a transbilayer attack, following flip-flop of detergent molecules across the lipid bilayer, and 2) extraction of membrane components directly by detergent micelles. The present study should help in the design of efficient solubilization protocols, accomplishing the often delicate balance between preserving functional properties of detergent sensitive membrane proteins and minimizing secondary aggregation and lipid content.

Animals↗
PubMed2003

Lipid rafts of purified mouse brain synaptosomes prepared with or without detergent reveal different lipid and protein domains.

Lipid rafts have been proposed to be important in a variety of functions including lipid transport, signal transduction and cell growth. There is increasing evidence that lipid rafts may play a role in cell functions in brain. Lipid rafts are typically isolated using a detergent such as Triton X-100. There has been, however, data from non-brain tissue indicating that preparation of lipid rafts using a detergent may represent different raft domains as compared with non-detergent preparation. The purpose of the present study was to compare protein and lipid markers of lipid rafts using a highly purified mouse synaptosomal fraction and non-detergent and detergent methods. The lipid raft marker proteins, alkaline phosphatase and flotillin, and the lipid markers, cholesterol and sphingomyelin, were highly enriched in lipid rafts prepared with detergent as compared with the non-detergent fraction. Enrichment of Na(+),K(+)-ATPase was greater in the non-detergent lipid raft fraction as compared with lipid rafts prepared with detergent. Lipid rafts from the nerve terminal of neurons prepared with or without detergents may represent different membrane domains each with unique specialized functions.

Animals↗
PubMed2003

Detergent organisation in crystals of monomeric outer membrane phospholipase A.

The structure of the detergent in crystals of outer membrane phospholipase A (OMPLA) has been determined using neutron diffraction contrast variation. Large crystals were soaked in stabilising solutions, each containing a different H(2)O/D(2)O contrast. From the neutron diffraction at five contrasts, the 12 A resolution structure of the detergent micelle around the protein molecule was determined. The hydrophobic beta-barrel surfaces of the protein molecules are covered by rings of detergent. These detergent belts are fused to neighbouring detergent rings forming a continuous three-dimensional network throughout the crystal. The thickness of the detergent layer around the protein varies from 7-20 A. The enzyme's active site is positioned just outside the hydrophobic detergent zone and is thus in a proper location to catalyse the hydrolysis of phospholipids in a natural membrane. Although the dimerisation face of OMPLA is covered with detergent, the detergent density is weak near the exposed polar patch, suggesting that burying this patch in the enzyme's dimer interface may be energetically favourable. Furthermore, these results indicate a crucial role for detergent coalescence during crystal formation and contribute to the understanding of membrane protein crystallisation.

Bacterial Outer Membrane Proteins↗
PubMed1989

Partition behavior of a nonionic detergent, octyl glucoside, between membrane and water phases, and its effect on membrane permeability.

The partition equilibrium of an nonionic detergent, octyl glucoside, between the membrane phase and water and the effect of the detergent on the barrier efficiency of the vesicle membrane were studied. When the detergent concentration was lower than 4 mM in the water phase, or a mole fraction of 0.3 in the membrane phase, the partition coefficient of the detergent was independent of the detergent concentration and was 75 M-1. This value was about twice the value predicted from the critical micelle concentration. In this concentration region, the permeability of Cl- was relatively low [(2-5) x 10(-10) cm/s]. When the detergent in the membrane phase exceeded a mole fraction of 0.3, the apparent partition coefficient decreased, and the permeability of Cl- abruptly increased. These observations are explained by the following model: If the effective cross-sectional areas of phospholipid molecules and detergent molecules are similar to each other, a detergent molecule in the membrane phase will be surrounded only by phospholipid molecules as long as the mole fraction of the detergent in the membrane phase is below 0.3, and in this condition, the membrane barrier efficiency is high. At a mole fraction higher than 0.3, the detergent molecules come into contact with each other, and the membrane barrier efficiency decreases.

Detergents↗
PubMed1998

On choosing a detergent for solution NMR studies of membrane proteins.

Translational diffusion coefficients and catalytic activities were measured for the integral membrane protein diacylglycerol kinase (DAGK) in a variety of types of detergent micelles. Despite the structural diversity of the detergents examined, the translational diffusion coefficients observed for DAGK spanned a fairly limited range of values: 2.7 to 4.7 (x10(-7) cm2/s). No general correlation was observed between the diffusion coefficients for the detergent-DAGK aggregates and the sizes of the corresponding protein-free micelles. These results indicate that the effective molecular weights of the DAGK-detergent aggregates were determined more by the structural properties of the protein than by the properties of the detergents. The catalytic activity of DAGK in detergents having medium-length alkyl chains such as dodecylphosphocholine or decylmaltoside was usually observed to be substantially higher than in short-chain detergents such as octylphosphocholine or octylglucoside. Taken together, the diffusion and activity results indicate that medium-chain detergents are generally preferred for use in NMR studies of complex membrane proteins because they are no worse than short-chained detergents in terms of increasing the effective molecular weight of the protein of interest while they are considerably better at maintaining native-like protein conformation. Among the 10 detergents examined, only sodium dodecylsulfate was observed to be unable to support DAGK activity under any conditions examined, suggest that this well-known protein denaturant should be used with care in studies of complex membrane proteins.

Detergents↗
PubMed1986

Role for topoisomerases in the release of DNA into the detergent-soluble fraction of eukaryotic cells.

Detergent-soluble DNA is the fraction (2-4%) of DNA that is released into the supernate upon mild detergent lysis. It is nonmitochondrial in origin. It labels efficiently with deoxy[3H]ribonucleosides and the labeling is prevented by inhibitors of polymerase alpha and ribonucleotide reductase. In previous publications we have characterized detergent-soluble DNA from splenocytes of immunologically activated mice. In this publication we show that incorporation of [3H]thymidine into detergent-soluble DNA is prevented by pretreatment with novobiocin, 4'-(9-acridinylamino)methanesulfon-m-anisidide (m-AMSA), and teniposide (VM26), three inhibitors of type II topoisomerases. Camptothecin, an inhibitor of type I topoisomerases, also reduces incorporation of [3H]thymidine but only to 50% of control levels. In addition to affecting incorporation of [3H]thymidine, preincubation with the topoisomerase II inhibitors m-AMSA and VM26 alters the amount of DNA recovered in the detergent-soluble fraction. At low concentrations of m-AMSA the amount of detergent-soluble DNA increases somewhat, whereas at higher drug concentrations a marked decrease is observed. Treatment with VM26 results in diminished amounts of DNA being released into the detergent-soluble fraction as well. However, maximal inhibition of detergent-soluble DNA release by VM26 requires the presence of camptothecin. Therefore, we suggest that topoisomerases play an important role in making a small part of lymphocyte chromatin detergent labile. Furthermore, these results are consistent with recent studies demonstrating a role for topoisomerases in yeast replication. Thus, the newly synthesized portion of detergent-soluble DNA may arise as DNA replication intermediates not yet stabilized into mature chromatin.

Aminoacridines↗
PubMed1996

Manifestation of cryptic fibroblast tissue factor occurs at detergent concentrations which dissolve the plasma membrane.

Cultured fibroblasts treated with increasing concentrations of detergents expressed only encrypted levels of tissue factor activity (measured by fX activation in the presence of fVIIa), characteristic of undamaged cells, until each detergent reached a critical concentration at which the cryptic tissue factor activity was manifested. Beyond the narrow ranges of concentrations over which the detergents stimulated tissue factor activity, the detergents were inhibitory. Studies with Triton X-100 and octyl glucoside revealed that manifestation of tissue factor activity coincided with breakdown of the plasma membrane. The magnitude of the increased tissue factor activity differed among detergents, with octyl glucoside giving the largest response. The tissue factor that was active after Triton X-100 treatment remained mostly associated with the insoluble cell residue, whereas the concentration of octyl glucoside which stimulated activity released tissue factor activity into the supernatant. Radiolabeled antibody against human tissue factor was used to show that a small percentage of the total accessible tissue factor remained in the insoluble fraction after treatment with either non-ionic detergent. Chromatographic analysis of lipids extracted from cells treated with detergents and dansyl chloride showed dansyl-reactivity of phosphatidylserine on intact cells, and solubilization of membrane lipids at sublytic concentrations of detergents. These findings reveal that there is a critical level of detergent-induced membrane damage at which tissue factor activity is maximally expressed, in essentially an all-or-none manner. The results are consistent with a major role for phospholipid asymmetry in regulation of tissue factor specific activity, but require either maintenance of asymmetry during sublytic detergent perturbation of the plasma membrane or additional control mechanisms.

Cell Death↗
PubMed2005

Wear of dentine in vitro by toothpaste abrasives and detergents alone and combined.

AIM: To measure in vitro the abrasion of dentine by toothpaste detergents and abrasives alone and combined. MATERIALS AND METHODS: Detergents used were tego betain, sodium lauryl sulphate (SLS), adinol and pluronic diluted to 1% w/v. Abrasives were three artificial silicas, tixosil 73 and 123 and Zeodent 113, and calcium carbonate used at 2.5% w/v. Flat human dentine specimens were brushed with aqueous detergent solutions or abrasive slurries, detergent abrasive slurries and water for 20,000 brush strokes. Dentine loss was measured by non-contacting profilometry at 10,000 and 20,000 strokes. Silica particle size distribution was measured by laser deflection. RESULTS: Loss of dentine occurred with all detergents, abrasives and detergent abrasion combinations, but was not linear with number of brush strokes. Water appeared to remove the smear layer only, but all detergents exceeded the predicted smear layer thickness. The silica abrasives differed in abrasion properties despite similar particle size distribution. Different detergents modulated the abrasives actions in mainly positive or mainly negative directions. CONCLUSIONS: Detergents appear able to attack the dentine surface to produce wear. Abrasives vary considerably in wear produced under similar conditions. Detergents modulate the effect of abrasives in a way that may reflect the rheological properties of the mixture.

Adolescent↗
PubMed2001

Accidental poisoning with household detergents.

UNLABELLED: Caustic substances and home detergent poisoning remain a threat to the health of young children. The aim of the present work was to estimate the occurrence of household poisoning due to detergents and to study some demographic and behavioral correlates. MATERIAL AND METHODS: Through systematic random sampling technique one tenth of all women attending pediatric and family medicine clinics in King Khalid University Hospital over two months were selected and interviewed to complete questionnaire. They were asked about history of poisoning due to detergents in their family in addition to their demographic-and practice regarding storage, use and disposal of detergents. RESULTS: The sample amounted to 318 mothers with mean age 34.2+/-7 13 years. 55(17 3%) reported history of poisoning due to detergents in their families Housewife mothers mothers with ?5 children, not reading detergents' labels, using detergents' containers for food and mixing different detergents; all were significantly associated (P<0.05) with higher rates of detergents poisoning in families (24.6%, 25.3%, 30.6%, 35.7% and 50%, respectively). RECOMMENDATIONS: health education programs concentrating with storage, use and hazards of detergents are recommended for mothers.

Accidents, Home↗
PubMed1989

Detergent structure and associated lipid as determinants in the stabilization of solubilized Ca2+-ATPase from sarcoplasmic reticulum.

The properties of detergents required to substitute the lipid environment of sarcoplasmic reticulum Ca2+-ATPase with retention of good functional properties were determined by the use of a large number of diverse detergents and delipidated enzyme. Detergents having an intermediate chain length (approximately equal to C12) and a polyoxyethylene glycol or carbohydrate polar group were optimal for Ca2+-ATPase function and stabilization, while detergents with short alkyl chain (C8) or bulky head groups and many zwitterionic detergents led to rapid inactivation. Under optimal conditions (including solubilization in the E1 state), stability of delipidated Ca2+-ATPase approximated that obtained by solubilization of Ca2+-ATPase with a layer of bound lipid. Some detergents (in particular long chain members of the Tween family) were characterized by an inadequate interaction with delipidated Ca2+-ATPase, resulting in biphasic inactivation. According to analytical ultracentrifugation and high performance liquid chromatography experiments, the rapid and slow components of biphasic inactivation were due to the formation of monomeric and oligomeric Ca2+-ATPase, respectively. It is concluded that both hydrophobic and polar interactions are important for the detergent effect and that solubilizing detergents of intermediate and short chain length may be bound as a monolayer, differently than the membrane lipid. Long chain detergents cause protein aggregation and, despite their resemblance to natural lipids, are inferior in their activity-retaining properties. The previous use of such detergents to prepare oligomeric Ca2+-ATPase with long term retention of activity (cf. Møller, J. V., Anderson, J. P., and le Maire, M. (1988) Methods Enzymol. 157, 261-270) is shown to depend on the presence of residual lipid in these preparations.

Animals↗
PubMed1993

Detergent binding as a measure of hydrophobic surface area of integral membrane proteins.

The mode by which four nonionic detergents interact with integral membrane proteins was studied by relating detergent binding to characteristic detergent monolayer and micellar dimensions and to the surface area of the hydrophobic sector of the proteins. The detergents used (C12E8, Triton X-100, dodecyl-beta-D-maltoside, and dodecyldimethylamineoxide) are efficient membrane solubilizers, which, according to our hydrodynamic analysis, form small approximately spherical micelles. Their binding by protomeric forms of bacteriorhodopsin, photosynthetic reaction center, sarcoplasmic reticulum Ca(2+)-ATPase, and cytochrome oxidase was measured after equilibration and delipidation, both by the use of successive chromatographies on silica gel and the use of agarose gel columns in combination with DEAE-cellulose chromatography. It was found that, despite detergent binding by silica gel, both chromatographic procedures gave equivalent and consistent results. The data obtained show systematic trends; thus dodecyldimethylamineoxide exhibited the highest binding levels, followed by dodecylmaltoside, whereas the polyethylene glycol detergents C12E8 and Triton X-100 had the lowest degree of binding. This ranking order is inversely related to the cross-sectional areas of these detergents in monolayers at an air-water interface and in micelles. Binding was reduced by aggregation of protomers, whereas the presence of strongly bound residual lipid slightly increased it. Among the membrane proteins with a high molecular mass (reaction center, Ca(2+)-ATPase, and cytochrome oxidase), relative binding could be related to the size of their hydrophobic sectors. On the other hand, bacteriorhodopsin bound somewhat more detergent per transmembrane helix, probably because of less steric hindrance, caused by the absence of a sizable hydrophilic domain in this protein. Theoretical calculations indicated monolayer binding of detergent to the hydrophobic surface of membrane proteins to be a better model for interaction with membrane proteins than binding of the detergents in micellar form.

Animals↗
PubMed1981

The detergent and salt effect on the light-harvesting chlorophyll a/b complex from green plants.

The light harvesting accessory pigment-protein complex (LHC) with a chlorophyll (Chl) a/b ratio of 1.2 was isolated by treating pea chloroplasts with Triton X-100. The LHC was used to investigate the action of ionic (sodium dodecyl sulfate) and non-ionic (Triton X-100) detergents. By optical methods (absorption and fluorescence spectra, measurements of fluorescence yield, phi, and lifetime, tau) two successive stages of the process were demonstrated, namely (1) interaction between detergent monomers and proteins and (2) solubilization of pigments into detergent micelles, which is facilitated by the presence of salts. The concentration ranges, characteristic of these stages, differ by 1.5-2 orders of magnitude for SDS, but slightly overlap for Triton X-100. At the second stage, certain changes occur in LHC absorption and fluorescence spectra. Several stable states of the LHC were established: (1) an aggregated state formed the presence of 10 mM MgSO4 with tau approximately 0.6 ns; (2) the dialyzed LHC with tau approximately 0.9 ns; (3) the states of the LHC in detergent solution with tau approximately 2.3, 2.9, 3.4 ns; (4) a 30 kilodalton monomer obtained by SDS-polyacrylamide gel electrophoresis with tau approximately 4.1 ns. The fluorescence parameters of the LHC states were compared with those of Chl a in detergent micelles (for the micelles tau = 5.6-6.0 ns). The tau/phi ratio (the criterion for emission heterogeneity) for the LHC in the absence of a detergent was shown to be higher at least by a factor of 3.5 than that for Chl a in the presence of a detergent. Successive additions of the detergent to the LHC cause gradual decrease in the tau/phi ratio, and for the LHC monomer it reaches practically the same value as for Chl a in detergent micelles. The results are discussed on the basis of the data obtained previously, It is suggested that in vivo LHCs do not form such aggregates as in water solution without a detergent.

Absorption↗
PubMedDate not supplied

The truth and consequences of enzymatic detergents.

Enzymatic detergents are widely used to clean gastrointestinal endoscopes before high-level disinfection. Although proper use of enzymatic detergents may appear straightforward, common misuses include failure to dilute the enzymatic detergent, overdilution of enzymatic detergent, use of expired enzymatic detergent, inadequate exposure time, and failure to rinse the enzymatic detergent from the instrument being cleaned. Each type of misuse has its own rationale. In these studies, the authors show by high-performance liquid chromatography that the type of enzymatic detergent and the dilution and rinsing of enzymatic detergents affect the amount of residual high-level disinfectant (ortho-phthalaldehyde) left on test segments of flexible endoscope insertion tubes. The authors also qualitatively demonstrate that proteinaceous material, which is stained a dark color by ortho-phthalaldehyde (OPA), remains on colonoscopes that have been cleaned with improperly diluted or rinsed enzymatic detergents. These findings emphasize the importance of diluting and using enzymatic detergents exactly as directed by their manufacturers to reduce bioburden and residual amounts of high-level disinfectant on flexible endoscopes.

Disinfectants↗
PubMedDate not supplied

The use of phosphate in detergents and possible replacements for phosphate.

About 5% of the total phosphate mined worldwide is used in detergents. The chemical form in which phosphate is used in detergents is predominantly pentasodium triphosphate (PSTP). The most significant feature for the use of PSTP in detergents is its ability to form soluble and strong complexes with calcium and magnesium ions. This provides a strong synergism with regard to detergency when PSTP is used in combination with synthetic surfactants. Other important features of PSTP are its ability to disperse dirt in the washing solution, its weak alkalinity, its crystalline form when dry (which enables production of crisp powders) and, last but not least, its toxicological acceptability. The development of PSTP for use in detergents has a history of over 25 years. In certain areas of highly developed countries where effluents from major centres of population can reach stagnant surface waters a rapid increase of eutrophication of these surface waters is observed. Phosphates are being recognized as one of the essential nutrients contributing to the eutrophication and detergents are one of the many sources of phosphate discharged to the environment. This is now causing demands for reduction in or even banning of the use of phosphates in detergents. Major reserach projects and some practical approaches to meeting these demands are described. The potential environmental impact of removing phosphate from detergents remains, however, doubtful, as it has been demonstrated in Sweden that phosphate removal by sewage treatment is the most effective measure to control phosphate discharges. This makes the case of phosphates in detergents an example of how science and technology can become entangled with politics.

Biodegradation, Environmental↗
PubMed1998

Opposite behavior of two isozymes when refolding in the presence of non-ionic detergents.

GroEL has a greater affinity for the mitochondrial isozyme (mAAT) of aspartate aminotransferase than for its cytosolic counterpart (cAAT) (Mattingly JR Jr, Iriarte A, Martinez-Carrion M, 1995, J Biol Chem 270:1138-1148), two proteins that share a high degree of sequence similarity and an almost identical spatial structure. The effect of detergents on the refolding of these large, dimeric isozymes parallels this difference in behavior. The presence of non-ionic detergents such as Triton X-100 or lubrol at concentrations above their critical micelle concentration (CMC) interferes with reactivation of mAAT unfolded in guanidinium chloride but increases the yield of cAAT refolding at low temperatures. The inhibitory effect of detergents on the reactivation of mAAT decreases progressively as the addition of detergents is delayed after starting the refolding reaction. The rate of disappearance of the species with affinity for binding detergents coincides with the slowest of the two rate-limiting steps detected in the refolding pathway of mAAT. Limited proteolysis studies indicate that the overall structure of the detergent-bound mAAT resembles that of the protein in a complex with GroEL. The mAAT folding intermediates trapped in the presence of detergents can resume reactivation either upon dilution of the detergent below its CMC or by adding beta-cyclodextrin. Thus, isolation of otherwise transient productive folding intermediates for further characterization is possible through the use of detergents.

Anilino Naphthalenesulfonates↗
PubMed1998

Alkaline detergent enzymes from alkaliphiles: enzymatic properties, genetics, and structures.

The cleaning power of detergents seems to have peaked; all detergents contain similar ingredients and are based on similar detergency mechanisms. To improve detergency, modern types of heavy-duty powder detergents and automatic dishwasher detergents usually contain one or more enzymes, such as protease, amylase, cellulase, and lipase. Alkaliphilic Bacillus strains are often good sources of alkaline extracellular enzymes, the properties of which fulfil the essential requirements for enzymes to be used in detergents. We have isolated numbers of alkaliphilic Bacillus that produce such alkaline detergent enzymes, including cellulase (CMCase), protease, alpha-amylase, and debranching enzymes, and have succeeded in large-scale industrial production of some of these enzymes. Here, we describe the enzymatic properties, genetics, and structures of the detergent enzymes that we have developed.

Amino Acid Sequence↗
PubMed1992

Detergents affect insulin binding, tyrosine kinase activity and oligomeric structure of partially purified insulin receptors.

Insulin receptor activities, i.e., insulin binding and tyrosine kinase activation depend on the lipid environment of the receptor. As detergent may disrupt or interfere with this environment, we investigated the effect of various common detergents on insulin receptor properties. Experiments were carried out (i) on solubilized and partially purified insulin receptor and (ii) on the receptor reconstituted into phosphatidylcholine vesicles. The detergents tested, Triton X-100, octyl-beta-D-glucopyranoside, octyl-beta-D-thioglucopyranoside, 3[(3-cholamidopropyl)dimethylammonio]propanesulfonic acid (Chaps), and Na deoxycholate affected the insulin receptor properties differently when compared with the control receptor in the absence of detergent. On the partially purified insulin receptor, Na deoxycholate inhibited both insulin receptor activities; octyl-beta-D-glucopyranoside and octyl-beta-D-thioglucopyranoside decreased insulin binding and kinase activation as their concentration increased, particularly above their respective critical micellar concentration (CMC). Triton X-100 was the only detergent which allowed an increase of insulin binding and kinase activation throughout the whole range of concentrations assayed. Reconstitution of the receptor into phosphatidylcholine vesicles protected the receptor from the direct effects of the detergents, for both the stimulation observed with Triton X-100 and the inhibition produced by the other detergents. In order to determine the effect of detergents on the oligomeric forms of the soluble insulin receptor, we investigated a new rapid sucrose gradient centrifugation technique. Insulin receptors were detected on the gradient by 125I insulin binding. For low concentrations of detergent, i.e., near the CMC, octylglucoside, Chaps, and Triton X-100 favored the (alpha 2 beta 2)2 oligomeric form of the receptor. Higher concentrations of Triton X-100 did not modify the polymeric state of the receptor. In contrast, octylglucoside and Chaps induced an increase in the sedimentation coefficient of the receptor which appeared as (alpha 2 beta 2)3 and (alpha 2 beta 2)4 forms. These alterations in the oligomerization status of the insulin receptor may explain the deleterious effects observed with both Chaps and octylglucoside at higher concentrations.

Centrifugation, Density Gradient↗
PubMed1976

Inactivation and reactivation of mitochondrial respiration by charged detergents.

Respiration of submitochondrial preparations can be inhibited by the cationic detergent cetyl trimethyl ammonium bromide and the anionic detergent sodium dodecyl sulfate in the range of 0.3-2 mumol of detergent per mg of mitochondrial membrane protein depending on the substrate and detergent used. This inhibition can be rapidly reversed by neutralizing a given detergent by the detergent of the opposite charge. At higher levels of the inhibiting detergent, no such reactivation was observed. Spin labeling assays of membrane structure were used to correlate structural effects with the loss and recovery of respiratory functions. Because the detergents progressively disrupt membrane structure, mitochondrial were cross-linked with bifunctional imidoesters to an extent that osmotic properties and detergent lysis were gone, but respiration remained. Such fixed respiring mitochondria also show inhibition reactivation phenomena.

Binding, Competitive↗