Lysosomal H+-translocating ATPase (H+-ATPase) was solubilized with lysophosphatidylcholine and reconstituted into liposomes (Moriyama, Y., Takano, T. and Ohkuma, S. (1984) J. Biochem. (Tokyo) 96, 927-930). In this stu...
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Lysosomal H+-translocating ATPase (H+-ATPase) was solubilized with lysophosphatidylcholine and reconstituted into liposomes (Moriyama, Y., Takano, T. and Ohkuma, S. (1984) J. Biochem. (Tokyo) 96, 927-930). In this study, the sensitivities of membrane-bound, solubilized and liposome-incorporated ATPase to various anions and drugs were measured in comparison with those of similar forms of mitochondria H+-ATPase (mitochondrial f0f1-ATPase) with the following results. (1) Bicarbonate and sulfite activated solubilized lysosomal H+-ATPase, but not the membrane-bound ATPase or ATPase incorporated into liposomes. All three forms of mitochondrial f0f1-ATPase were activated by these anions. (2) All three forms of both lysosomal H+-ATPase and mitochondrial f0f1-ATPase were strongly inhibited by SCN-, NO3- and f-, but scarcely affected by Cl-, Br- and SO42-. (3) The solubilized lysosomal H+-ATPase was strongly inhibited by azide, quercetin, 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl), 4-acetamido-4''-isothiocyanatostilbene-2,2''-disulfonic acid (SITS), 4,4''-diisothiocyanatostilbene-2,2''-disulfonic acid (DIDS) and oligomycin. Its sensitivity was almost the same as that of mitochondrial f0f1-ATPase. Neither membrane-bound ATPase nor ATPase incorporated into liposomes was affected appreciably by these drugs. These results indicate that the sensitivity to anions and drugs of lysosomal H+-ATPase depends on the form of the enzyme and that the sensitivity of the solubilized lysosomal H+-ATPase is very similar to that of mitochondrial f0f1-ATPase. On the other hand, the two ATPases differ in their sensitivity to N-ethylmaleimide and pyridoxal phosphate;only the mitochondrial ATPase is inhibited by pyridoxal phosphate whereas only the lysosomal ATPase is inhibited by N-ethylmaleimide.
The distribution functions of central and noncentral chi-square, f and beta random variables are expressed as special cases of the distribution function of an indefinite quadratic form. Some of these distribution func...
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The distribution functions of central and noncentral chi-square, f and beta random variables are expressed as special cases of the distribution function of an indefinite quadratic form. Some of these distribution functions, particularly the doubly noncentral cases, have traditionally involved fairly complicated expressions. The form presented in this paper is computationally straightforward and is attractive because it presents these related distributions as special cases of a single equation.
The binding offive monoclonal antibodies to mitochondrial f1-ATPase has been studied. Competition experiments between monoclonal antibodies demonstrate that these antibodies recognize four different antigenic sites a...
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The binding offive monoclonal antibodies to mitochondrial f1-ATPase has been studied. Competition experiments between monoclonal antibodies demonstrate that these antibodies recognize four different antigenic sites and provide information on the proximity of these sits. The accessibility of the epitopes has been compared for f1 integrated in the mitochondrial membrane, for purified .beta.-subunit and for purified f1 maintained in its active form by the presence of nucleotides or inactivated either by dilution in the absence of ATP or by urea treatment. The three anti-.beta. monoclonal antibodies bound more easily to the .beta.-subunit than to active f1, and recognized equally active f1 and f1 intergrated in the membrane, indicating that their antigenic sites are partly buried similarly in purified or membrane-bound f1 and better exposed in the isolated .beta.-subunit. In addition, unfolding f1 by urea srongly increased the binding of one anti-.beta. monoclonal antibody (14 D5) indicating that this domain is at least partly shielded inside the .beta.-subunit. One anti-.alpha. monoclonal antibody (20 D6) bound poorly to f1 integrated in the membrane, while the other (7 B3) had a higher affinity for f1 integrated in the membrane than for soluble f1. Therefore, 20 D6 recognizes an epitope of the .alpha.-subunit buried inside f1 integrated in the membrane, while 7 B3 binds to a domain of the .alpha.-subunit well exposed at the surface of the inner face of the mitochondrial membrane.
The site of biosynthesis of transformylase, an enzyme of plastid and mitochondrial protein synthesizing system, was studied in autotrophic and heterotrophic E. gracilis cells. In light-grown cells and in resting dark-...
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The site of biosynthesis of transformylase, an enzyme of plastid and mitochondrial protein synthesizing system, was studied in autotrophic and heterotrophic E. gracilis cells. In light-grown cells and in resting dark-grown cells cultivated in light, chloramphenicol (CAP) didn''t modify the level of transformylase activity. The enzyme from dark-grown cells was unaffected by the addition of ethidium bromide to the medium, whereas transformylase accumulation was stimulated by addition of CAP. Apparently both plastidial and mitochondrial transformylase are synthesized on cytoplasmic ribosomes. A regulation mechanism for the etioplast transformylase is proposed.
We prepared two types of E. coli f1 by slightly different gel filtration procedures of the purified f1: f1(II) contained about 2 mol, and f1(V) about 5 mol of bound adenine nucleotides per mol of the enzyme. Thus f1(I...
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We prepared two types of E. coli f1 by slightly different gel filtration procedures of the purified f1: f1(II) contained about 2 mol, and f1(V) about 5 mol of bound adenine nucleotides per mol of the enzyme. Thus f1(II) had more than 2, possibly 3, vacant catalytic sites, while f1(V) had less than one vacant catalytic site. The rate of ATP hydrolysis in uni-site catalysis (in the presence of inorganic phosphate) was about 3-fold higher with f1(II) than with f1(V), suggesting that ADP and inorganic phosphate bound at the catalytic sites off1(V) changed the kinetics of uni-site catalysis significantly.
A sucrose:sucrose 1f-.beta.-D-fructosyltransferase (EC 2.4.1.9) has been purified from onion seeds by fractionation with ammonium sulfate and then by chromatography on DEAE-cellulose. CM-cellulose, octyl-Sepharose and...
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A sucrose:sucrose 1f-.beta.-D-fructosyltransferase (EC 2.4.1.9) has been purified from onion seeds by fractionation with ammonium sulfate and then by chromatography on DEAE-cellulose. CM-cellulose, octyl-Sepharose and Sephadex G-200. The purified enzyme which showed a single protein band on polyacrylamide gel electrophoresis was free from the other fructosyltransferases, catalyzed fructosyltransfer from sucrose to another sucrose to form 1-kestose and glucose, and also in some degree transferred a fructosyl residue from sucrose to raffinose and stachyose but did not to 1-kestose and nystose. The enzyme had a MW of .apprx. 68,000, an optimum pH of 5.4 and Km of 0.083 M, was stable at ***.-***. for 10 min, and was inhibited by Hg2+, Ag+, Mn2+ and p-chloromercuribenzoate.
In Lithuania, two species of the genus fragaria L. (Rosaceae), f. vesca L. and f. viridis Weston, occur naturally in the wild and two others, f. moschata Weston and *** Duchesne ex Rozier are found escaped from cultiv...
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In Lithuania, two species of the genus fragaria L. (Rosaceae), f. vesca L. and f. viridis Weston, occur naturally in the wild and two others, f. moschata Weston and *** Duchesne ex Rozier are found escaped from cultivation. The main objective of this study was to establish the variation pattern in the content of chlorogenic acid, rutin and hyperoside in leaves and fruits of the native Lithuanian species. In this work, the chemical polymorphisms of different fragaria species were studied by growing plants side by side under the same cultivated field conditions. f. vesca fruits had the highest rutin (1.38 +/- 0.19mg g(1) DM), hyperoside (0.69 +/- 0.10mg g(1) DM) and chlorogenic acid (2.25 +/- 0.34mg g(1) DM) content, followed by f. viridis and f. moschata. Our results showed that the leaves should be taken into account as important rutin and hyperoside contributors for strawberries.
f 1 -ATPases from bovine mitochondria and Escherichia coli both contain 5 subunits named α, β, γ, δ and ε. Sequence analysis shows that the δ subunits are not related, nor are the ε subunits. The counterpart of...
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f 1 -ATPases from bovine mitochondria and Escherichia coli both contain 5 subunits named α, β, γ, δ and ε. Sequence analysis shows that the δ subunits are not related, nor are the ε subunits. The counterpart of mitochondrial δ is bacterial ε. The subunit equivalent to bacterial δ is mitochondrial oligomycin sensitivity conferral protein.
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