SEARCH · PubMed Health

Results for “Condensates”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 217 records · Page 12Linked to original sources

PubMed1999

Structural effects of cobalt-amine compounds on DNA condensation.

Light scattering and electron microscopy have been used to investigate the structural effects of the trivalent complexes hexaammine cobalt (III) chloride (Cohex), tris(ethylenediamine) cobalt(III) chloride (Coen), and cobalt(III) sepulchrate chloride (Cosep) on DNA condensation. These cobalt-amine compounds have similar ligand coordination geometries but differ slightly in size. Their hydrophobicity is in the order Cosep > Coen > Cohex, according to the numbers of methylene groups in these ligands. All of these compounds effectively precipitate DNA at high concentrations; but despite a lower surface charge density, Cosep condenses DNA twice as effectively as Coen or Cohex. UV and CD measurements of the supernatants of cobalt-amine/DNA solutions reveal a preferential binding of Delta-Coen over Lambda-Coen to the precipitated DNA, but there is no chiral selectivity for Cosep. Competition experiments show that the binding strengths of these three cobalt-amine compounds to aggregated DNA are comparable. A charge neutralization of 88-90% is required for DNA condensation. Our data indicate that 1) electrostatic interaction is the main driving force for binding of multivalent cations to DNA; 2) DNA condensation is dependent on the structure of the condensing agent; and 3) the hydration pattern or polarization of water molecules on the surface of condensing agents plays an important role in DNA condensation and chiral recognition.

Amines↗

PubMed2002

Amorphous and condensed organic matter domains: the effect of persulfate oxidation on the composition of soil/sediment organic matter.

The composition of amorphous and condensed soil/sediment organic matter (SOM) domains was investigated for one soil sample and four sediment samples. These samples were oxidized with persulfate to remove amorphous SOM, before and after which the composition of SOM was studied by thermogravimetric analysis, pyrolysis-GC/MS, and cross polarization magic angle spinning 13C-NMR. Comparison of the SOM composition before and after oxidation showed that condensed SOM was more thermostable and less polar than amorphous SOM. Condensed SOM was relatively low in O-alkyl C and carboxyl C and it was likely to contain only small amounts of labile organic components (carbohydrates, peptides, fatty acids). Apart from these general characteristics, the composition of the condensed and amorphous domains appeared to be highly dependent on the origin and nature of the SOM investigated. Condensed domains in relatively undecomposed SOM were enriched in aliphatic C, whereas condensed domains in relatively weathered SOM were enriched in aromatic C. Altogether, the compositional changes upon persulfate oxidation were similar to the compositional changes upon humification, which supports the idea that weathered SOM is more condensed than the original material.

Carbon Isotopes↗

PubMed2001

Effect of pyrolysis temperature on the mutagenicity of tobacco smoke condensate.

Tobacco smoke aerosols with fewer mutagens in the particulate fraction may present reduced risk to the smoker. The objective of this study was to test the hypothesis that the temperature at which tobacco is pyrolyzed or combusted can affect the mutagenicity of the particulate fraction of the smoke aerosol. Tobacco smoke aerosol was generated under precisely controlled temperature conditions from 250 to 550 degrees C by heating compressed tobacco tablets in air. The tobacco aerosols generated had a cigarette smoke-like appearance and aroma. The tobacco smoke aerosol was passed through a Cambridge filter pad to collect the particulate fraction, termed the smoke condensate. Although condensates of tobacco smoke and whole cigarette mainstream smoke share many of the same chemical components, there are physical and chemical differences between the two complex mixtures. The condensates from smoke aerosols prepared at different temperatures were assayed in the Ames Salmonella microsome test with metabolic activation by rat liver S9 using tester strains TA98 and TA100. Tobacco smoke condensates were not detectably mutagenic in strain TA98 when the tobacco smoke aerosol was generated at temperatures below 400 degrees C. Above 400 degrees C, condensates were mutagenic in strain TA98. Similarly, condensates prepared from tobacco smoke aerosols generated at temperatures below 475 degrees C were not detectably mutagenic in strain TA100. In contrast, tobacco tablets heated to temperatures of 475 degrees C or greater generated smoke aerosol that was detectably mutagenic as measured in TA100. Therefore, heating and pyrolyzing tobacco at temperatures below those found in tobacco burning cigarettes reduces the mutagenicity of the smoke condensate. Highly mutagenic heterocyclic amines derived from the pyrolysis of tobacco leaf protein may be important contributors to the high temperature production of tobacco smoke Ames Salmonella mutagens. The relevance of these findings regarding cancer risk in humans is difficult to assess because of the lack of a direct correlation between mutagenicity in the Ames Salmonella test and carcinogenicity.

Aerosols↗

PubMed2001

Roscovitine, a specific inhibitor of cyclin-dependent protein kinases, reversibly inhibits chromatin condensation during in vitro maturation of porcine oocytes.

In the present study the effects of roscovitine on the in vitro nuclear maturation of porcine oocytes were investigated. Roscovitine, a specific inhibitor of cyclin-dependent protein kinases, prevented chromatin condensation in a concentration-dependent manner. This inhibition was reversible and was accompanied by non-activation of p34cdc2/histone H1 kinase. It also decreased enzyme activity of MAP kinase, suggesting a correlation between histone H1 kinase activation and the onset of chromatin condensation. The addition of roscovitine (50 microM) to extracts of metaphase II oocytes revealed that the MAP kinase activity was not directly affected by roscovitine, which indicates a possible link between histone H1 and MAP kinase. Chromatin condensation occurred between 20 and 28 h of culture of cumulus-oocyte complexes (COCs) in inhibitor-free medium (germinal vesicle stage I, GV1: 74.6% and 13.7%, respectively). Nearly the same proportion of chromatin condensation was detected in COCs incubated initially in inhibitor-free medium for 20-28 h and subsequently in roscovitine-supplemented medium (50 microM) for a further 2-10 h (GV I: 76.2% and 18.8%, respectively). This observation indicates that roscovitine prevents chromatin condensation even after an initial inhibitor-free cultivation for 20 h. Extending this initial incubation period to > or = 22 h led to an activation of histone H1 and MAP kinase and increasing proportions of oocytes exhibiting chromatin condensation in the presence of roscovitine. It is concluded that histone H1 kinase is involved in the induction of chromatin condensation during in vitro maturation of porcine oocytes.

Animals↗

PubMed1984

Dynamics of DNA condensation.

The condensation of DNA induced by spermine and spermidine is investigated by equilibrium titrations and stopped-flow and field-jump experiments using scattered light detection. The spermine concentration required for the cooperative condensation process is measured at different DNA concentrations; these data are used to evaluate both the condensation threshold degree of spermine binding and the binding constant of spermine according to an excluded-site model. Stopped-flow measurements of the spermine-induced condensation demonstrate the existence of two processes: (1) A "fast" reaction is observed in the millisecond time range, when the reactant concentrations are around 1 microM; it is associated with a characteristic induction period and is assigned to the intramolecular condensation reaction. (2) A slow reaction with time constants of, e.g., 100 s strongly dependent upon both spermine and DNA concentrations is assigned to an intermolecular DNA association. The unusual time course of the intramolecular condensation reaction with the induction period provides evidence for a "threshold kinetics". During the induction period, spermine molecules are bound to DNA, but the degree of binding remains below the threshold value. As soon as the degree of ligand binding arrives at the threshold, the DNA is condensed in a relatively fast reaction. Model calculations of the spermine binding kinetics according to an excluded-site model demonstrate that the spermine molecules bound to DNA are mobile along the double helix. A comparison of the experimental data with the results of Monte Carlo simulations suggests a rate constant of approximately 200 s-1 for spermine movement by one nucleotide residue.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacteriophage lambda↗

PubMed2001

DNA condensation by polyamines: a laser light scattering study of structural effects.

Polyamines such as spermidine and spermine are abundant in living cells and are believed to aid in the dense packaging of cellular DNA. DNA condensation is a prerequisite for the transport of gene vectors in living cells. To elucidate the structural features of polyamines governing DNA condensation, we studied the collapse of lambda-DNA by spermine and a series of its homologues, H2N(CH2)3NH(CH2)n=2-12NH(CH2)3NH2 (n = 4 for spermine), using static and dynamic light scattering techniques. All polyamines provoked DNA condensation; however, their efficacy varied with the structural geometry of the polyamine. In 10 mM sodium cacodylate buffer, the EC50 values for DNA condensation were comparable (4 +/- 1 microM) for spermine homologues with n = 4-8, whereas the lower and higher homologues provoked DNA condensation at higher EC50 values. The EC50 values increased with an increase in the monovalent ion (Na+) concentration in the buffer. The slope of a plot of log [EC50(polyamine4+)] against log [Na+] was approximately 1.5 for polyamines with even number values of n, whereas the slope value was approximately 1 for compounds with odd number values of n. Dynamic light scattering measurements showed the presence of compact particles with hydrodynamic radii (Rh) of about 40-50 nm for compounds with n = 3-6. Rh increased with further increase in methylene chain length separating the secondary amino groups of the polyamines (Rh = 60-70 nm for n = 7-10 and >100 nm for n = 11 and 12). Determination of the relative binding affinity of polyamines to DNA using an ethidium bromide displacement assay showed that homologues with n = 2 and 3 as well as those with n > 7 had significantly lower DNA binding affinity compared to spermine and homologues with n = 5 and 6. These data suggest that the chemical structure of isovalent polyamines exerts a profound influence on their ability to recognize and condense DNA, and on the size of the DNA condensates formed in aqueous solution.

Bacteriophage lambda↗

PubMed2005

A macrothermodynamic approach to the limit of reversible capillary condensation.

The threshold of reversible capillary condensation is a well-defined thermodynamic property, as evidenced by corresponding states treatment of literature and experimental data on the lowest closure point of the hysteresis loop in capillary condensation-evaporation cycles for several adsorbates. The nonhysteretical filling of small mesopores presents the properties of a first-order phase transition, confirming that the limit of condensation reversibility does not coincide with the pore critical point. The enthalpy of reversible capillary condensation can be calculated by a Clausius-Clapeyron approach and is consistently larger than the condensation heat in unconfined conditions. Calorimetric data on the capillary condensation of tert-butyl alcohol in MCM-41 silica confirm a 20% increase of condensation heat in small mesopores. This enthalpic advantage makes easier the overcoming of the adhesion forces by the capillary forces and justifies the disappearing of the hysteresis loop.

Journal Article↗

PubMed2001

Seasonal changes in human sperm chromatin condensation.

PURPOSE: The aim of this study was to investigate possible seasonal changes in human sperm parameters, especially chromatin condensation. METHOD: In a first run, 3155 patients attending the andrological outpatient clinic at the Centre of Dermatology and Andrology at Justus Liebig University, Giessen, Germany, from January 1992 to October 1995 were examined for sperm count, motility, vitality, and chromatin condensation. RESULTS: The respective results were correlated according to season. Significant seasonal changes were observed in chromatin condensation and sperm count, with mean maximum values (for chromatin condensation and sperm count) of 86.24% aniline blue-negative spermatozoa in January and 68.75 x 10(6) mL-1 in April. To confirm the observation of seasonal changes in sperm chromatin condensation in Germany on the Southern Hemisphere, 179 patients attending the Reproductive Biology Unit at Tygerberg Hospital, Tygerberg, South Africa, were examined by means of the aniline blue stain from April 1999 to April 2000. For chromatin condensation, a significant seasonal change shifted by 4-5 months was observed on the Southern Hemisphere. However, no seasonal variations could be found for the sperm count. CONCLUSIONS: Our results clearly demonstrate seasonal changes in sperm count and chromatin condensation. In contrast, no circannual relation was observed for motility and vitality.

Chromatin↗

PubMed1997

DNA renaturation activity of the SMC complex implicated in chromosome condensation.

Chromosome condensation occurs in mitosis before the separation of sister chromatids, and requires DNA topoisomerase II and a group of proteins called SMCs. The resulting condensed chromosomes in metaphase have a complex hierarchical structure. SMCs, the components of condensed chromosomes, are also required for the separation of sister chromatids and gene dosage compensation, and are found in a range of organisms from yeasts to mammals. However, the mechanisms by which the SMCs contribute to chromosome condensation are unknown. We have studied chromosomes in fission-yeast SMC mutants cut3-477 and cut14-208, which remain largely non-condensed during mitosis at the restrictive temperature (36 degrees C). To test their role in DNA condensation, we isolated the proteins Cut3 and Cut14 as an oligomeric complex, and tested their interactions with isolated DNA. The complex efficiently promoted the DNA renaturation reactions (the winding up of single-strand DNAs into double helical DNA) as much as approximately 70-fold more efficiently than RecA, which is a bacterial protein with similar activity. The activity of the mutant complex was heat sensitive. As DNA winding by renaturation is a potential cause of supercoiling, the SMC complex may be implicated in promoting the higher-order DNA coiling found in condensed chromosomes.

Chromosomes, Fungal↗

PubMed2005

Bone regeneration in a rat cranial defect with delivery of PEI-condensed plasmid DNA encoding for bone morphogenetic protein-4 (BMP-4).

Gene therapy approaches to bone tissue engineering have been widely explored. While localized delivery of plasmid DNA encoding for osteogenic factors is attractive for promoting bone regeneration, the low transfection efficiency inherent with plasmid delivery may limit this approach. We hypothesized that this limitation could be overcome by condensing plasmid DNA with nonviral vectors such as poly(ethylenimine) (PEI), and delivering the plasmid DNA in a sustained and localized manner from poly(lactic-co-glycolic acid) (PLGA) scaffolds. To address this possibility, scaffolds delivering plasmid DNA encoding for bone morphogenetic protein-4 (BMP-4) were implanted into a cranial critical-sized defect for time periods up to 15 weeks. The control conditions included no scaffold (defect left empty), blank scaffolds (no delivered DNA), and scaffolds encapsulating plasmid DNA (non-condensed). Histological and microcomputed tomography analysis of the defect sites over time demonstrated that bone regeneration was significant at the defect edges and within the defect site when scaffolds encapsulating condensed DNA were placed in the defect. In contrast, bone formation was mainly confined to the defect edges within scaffolds encapsulating plasmid DNA, and when blank scaffolds were used to fill the defect. Histomorphometric analysis revealed a significant increase in total bone formation (at least 4.5-fold) within scaffolds incorporating condensed DNA, relative to blank scaffolds and scaffolds incorporating uncondensed DNA at each time point. In addition, there was a significant increase both in osteoid and mineralized tissue density within scaffolds incorporating condensed DNA, when compared with blank scaffolds and scaffolds incorporating uncondensed DNA, suggesting that delivery of condensed DNA led to more complete mineralized tissue regeneration within the defect area. This study demonstrated that the scaffold delivery system encapsulating PEI-condensed DNA encoding for BMP-4 was capable of enhancing bone formation and may find applications in other tissue types.

Animals↗

PubMed2002

The Claisen condensation in biology.

The mechanism for carbon-carbon bond formation used in the biosynthesis of natural products such as fatty acids and polyketides is a decarboxylating Claisen condensation. The enzymes that catalyze this reaction in various bacterial systems, collectively referred to as condensing enzymes, have been intensively studied in the past several decades, and members of the family have been crystallized. The condensing enzymes share a common 3-dimensional fold, first described for the biosynthetic thiolase I that catalyzes a non-decarboxylating Claisen condensation, although they share little similarity at the amino acid level. Their active sites, however, possess significant similarities. The initiation condensing enzymes use CoA primers and possess a catalytic triad of Cys, His, Asn; and the elongating condensing enzymes that exclusively use ACP thioesters have a triad of Cys, His, His. These active site differences affect the sensitivity of the respective enzymes to the antibiotics thiolactomycin and cerulenin. Different reaction mechanisms have been proposed for the condensing enzymes. This review covers the recent structural and mechanistic data to see if a unifying hypothesis for the reaction mechanism catalyzed by this important family of enzymes can be established.

Animals↗

PubMed1999

Comparison of two vertical condensation obturation techniques: Touch 'n Heat modified and System B.

AIM: The aims of this study were firstly to compare the area of canal occupied by gutta-percha, sealer or voids using the System B heating device with that obtained by a modified vertical condensation technique using the Touch 'n Heat: and secondly to compare the temperature changes at the root canal wall and external root surface during obturation with the above techniques. METHODOLOGY: Forty-five resin blocks, each with a standardized, simulated, prepared main root canal and five lateral canals, were assigned to three equal experimental groups. The canals were obturated using either the System B technique at two different temperature settings, or vertical condensation with a Touch 'n Heat instrument as the heat source. A heat transfer model was used to simultaneously record internal and external root surface temperature elevations during obturation by the three techniques. Data were analysed using unpaired Student's t-test and Mann-Whitney U-test. RESULTS: Both obturation techniques produced root fillings consisting of over 90% gutta-percha at most levels, although the percentages of sealer and voids 2-3 mm from the working length following System B obturation were higher than those found following modified vertical condensation. Modified vertical condensation resulted in more gutta-percha in lateral canals. Obturation was accomplished more quickly using the System B, and temperature elevations produced during obturation with the System B were significantly less (P < 0.001) than with vertical condensation. An elevation of external root surface temperature by more than 10 degrees C occurred during vertical condensation. CONCLUSIONS: The results suggest that the System B may produce an acceptable obturation and that the use of a Touch 'n Heat source during vertical condensation may result in damage to the periodontium.

Gutta-Percha↗

PubMed2002

An efficient and reproducible method for measuring hydrogen peroxide in exhaled breath condensate.

We investigated the sensitivity and reproducibility of a test procedure for measuring hydrogen peroxide (H202) in exhaled breath condensate and the effect of storage of the condensate on the H2O2 concentration, and compared the results to previous studies. Twenty stable COPD patients breathed into our collecting device twice for a period of 10 min. The total exhaled air volume (EAV) and condensate volume were measured both times and the H2O2 concentration of the condensate was determined fluorimetrically. The concentration was measured again after freezing the reaction product at -70 degrees C for a period of 10, 20 and 40 days. We collected 2-5 ml condensate in 10 min. The EAV and condensate volumes were strongly correlated. There was no significant difference between the mean H2O2 concentration of the first and second test. We obtained a detect on limit for the H2O2 concentration of 0.02 micromoll(-1). The H2O2 concentration appeared to remain stable for a period up to 40 days of freezing. Compared to previous studies we developed a more efficient breath condensate collecting device and obtained a lower H2O2 detection limit. The measurement of exhaled H2O2 was reproducible. In addition, storage of the samples up to 40 days showed no changes in H2O2 concentration.

Aged↗

PubMed2006

Matrix effects in the carbon 1s near edge x-ray absorption fine structure spectra of condensed alkanes.

The carbon 1s near edge x-ray absorption fine structure (NEXAFS) spectra of simple gaseous alkane molecules differ from the spectra of the same alkane molecules in the condensed phase. The origin of these large, systematic differences is poorly understood. The NEXAFS spectra of gaseous alkanes are interpreted as a progression of core-->Rydberg transitions with distinctive vibronic structure. The interpretation of the NEXAFS spectra of condensed phase alkanes is varied. Specifically, the degree of Rydberg character in the pre-edge core excited states of condensed alkanes is controversial. We determined the character of core excited states in condensed alkanes with a combination of experiment and computational study. From this, we have determined the nature of matrix effects for these species. The high-resolution carbon 1s NEXAFS spectrum of gaseous neopentane is dramatically different from its condensed phase spectrum, a striking illustration of the dramatic spectroscopic changes that occur upon condensation. High quality ab initio calculations of a cluster designed to model the solid phase environment provide definitive evidence for the reduction of Rydberg character and support the assignment of sigma*C-H) valence character in the pre-edge features in the NEXAFS spectra of condensed alkanes.

Journal Article↗

PubMed1974

Detection of mutagenic activity in cigarette smoke condensates.

The Salmonella typhimurium microsomal test system for mutagenic activity was successfully used to detect the presence of mutagenic compounds in the smoke condensates of several types of cigarettes. The condensates were shown to contain compounds which could cause frameshift mutations when activated by microsomal enzymes. An analysis of fractions of smoke condensate revealed that the detected mutagenic activity was distributed in several of the fractions. Most of the activity of the whole condensate was in basic fractions and in a weakly acidic fraction. Condensates from cigarettes treated with magnesium nitrate differed from other condensates in two respects. They contained frameshift mutagens which did not require microsomal activation and mutagens which could cause base-pair substitution mutations. Although the detection system usually employs rat liver microsomal preparations, a rat lung microsomal preparation was also found to be capable of converting smoke condensates and known chemical carcinogens into mutagenic forms.

Animals↗

PubMed2002

Condensation of DNA by spermatid basic nuclear proteins.

Two transition proteins, TP1 and TP2, participate in the repackaging of the spermatid genome early in mammalian spermiogenesis, coincident with the first detectable changes in chromatin condensation. Using an optical trap and a two-channel flow cell to move single DNA molecules into buffer containing protein, we have measured the rates of DNA condensation and decondensation induced by the binding of Syrian hamster transition proteins TP1 and TP2 and protamines P1 and P2. The results show that both transition proteins condense free DNA, with rates similar to those of protamine 1 and 2. DNA molecules condensed with TP1 were significantly less stable than DNA condensed by protamine or by TP2. Experiments conducted with a peptide corresponding to the C-terminal 25 residues of TP2 showed that this domain is responsible for condensing DNA. Experiments conducted with two fragments of TP1 containing arginine and lysine residues demonstrated that DNA binding by TP1 must involve more than these basic sequences. Zinc facilitated the condensation of DNA by P2 but not by TP2. The dissociation rates of TP2 and P2 from DNA were not affected by the addition of zinc.

Amino Acid Sequence↗

PubMed1985

The role of condensed tannins in the nutritional value of Lotus pedunculatus for sheep. Rates of body and wool growth.

Lotus pedunculatus (cv. Grasslands Maku) grown on acid low-fertility soil and containing high concentrations of condensed tannin (76-90 g/kg dry matter (DM] was grazed by growing sheep for 31-42 d periods in three experiments. In Expt 2 an additional group of lambs grazed areas oversown with white clover (Trifolium repens) and red clover (Trifolium pratense). Lambs were transferred from grazing ryegrass (Lolium perenne)-white clover straight on to lotus in all experiments (unconditioned sheep). In Expt 3 a second group was included which had grazed high-tannin lotus for a pre-experimental period of 8 weeks (conditioned sheep). Effects of condensed tannin on body and wool growth were assessed by studying responses to daily oral administration of polyethylene glycol (PEG; molecular weight 3350, 75-100 g/d). PEG forms a complex with condensed tannin, which is assumed to be inert in its passage through the digestive system, and so effectively reduces the nutritional effects attributable to high condensed-tannin concentrations. Live-weight gain (LWG) in the absence of PEG was low (27-125 g/d) for sheep grazing high-tannin lotus, and PEG administration increased LWG by 41-61 g/d and increased wool growth. In Expt 3, responses to PEG supplementation tended to be less with conditioned than with unconditioned sheep, indicating that conditioned sheep had partially adapted to the high-tannin diet. PEG supplementation had no effect on either LWG or wool growth of sheep grazing areas oversown with mixed clovers, confirming its effects as specific to forages containing condensed tannins. These experiments therefore conclusively show that high concentrations of condensed tannin induced by growing Lotus pedunculatus under low soil fertility conditions prevent maximum expression of LWG and wool growth in grazing sheep. These results contrast with high LWG (153-315 g/d) observed in growing sheep grazing the same lotus cultivar grown in high fertility soil and containing 20 g condensed tannin/kg DM, a level considered to be nutritionally beneficial.

Administration, Oral↗

PubMed2002

Distinct but overlapping domains of AKAP95 are implicated in chromosome condensation and condensin targeting.

A-kinase (or PKA)-anchoring protein AKAP95 is a zinc-finger protein implicated in mitotic chromosome condensation by acting as a targeting molecule for the condensin complex. We have identified determinants of chromatin-binding, condensin-targeting and chromosome-condensation activities of AKAP95. Binding of AKAP95 to chromatin is conferred by residues 387-450 and requires zinc finger ZF1. Residues 525-569 are essential for condensation of AKAP95-free chromatin and condensin recruitment to chromosomes. Mutation of either zinc finger of AKAP95 abolishes condensation. However, ZF1 is dispensable for condensin targeting, whereas the C-terminal ZF2 is required. AKAP95 interacts with Xenopus XCAP-H condensin subunit in vitro and in vivo but not with the human hCAP-D2 subunit. The data illustrate the involvement of overlapping, but distinct, domains of AKAP95 for condensin recruitment and chromosome condensation and argue for a key role of ZF1 in chromosome condensation and ZF2 in condensin targeting. Moreover, condensin recruitment to chromatin is not sufficient to promote condensation.

Adenosine Triphosphatases↗