Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P39060 (endostatin)
 2,284 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The tonoplast of Tradescantia virginiana L. was prepared from leaf cells and then solubilized with deoxycholate (DOC) and n-octyl-beta-D-glucoside (n-OG). Three major polypeptides (68, 60, 16 kDa) and several other minor components were isolated. These polypeptides were reconstituted in soybean phospholipids (asolectin). The H(+) pump activity was investigated with the reconstituted system as well as with the tonoplast. In both cases, the quinacrine-fluorescence quenching was observed in the presence of ATP-Mg(2+), indicating the H(+) pumping. The H(+) pump activity was inhibited by gramicidin D, a channel-forming ionophore, and by KNO(3), an inhibitor specific to tonoplast-type (V-type) H(+)-ATPase.
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PMID:Isolation of H+ -translocating ATPase in tonoplast of Tradescantia virginiana L. leaf cells. 1244 53

The tonoplast ATPase from corn coleoptile membranes was solubilized using a two-step procedure consisting of a pretreatment with 0.15% (w/v) deoxycholate to remove 60% of the protein, and 40 millimolar octyl-glucoside to solubilize the ATPase. During ultracentrifugation, the solublized ATPase entered a linear sucrose gradient faster than the majority of the protein, resulting in an 11-fold purification over the initial specific activity. The partially purified ATPase was almost completely inhibited by KNO(3) with an estimated K(i) of 10 millimolar. The specific activity of the KNO(3)-sensitive ATPase was increased 29-fold during purification. N,N'-Dicyclohexylcarbodiimide also completely inhibited the ATPase with half-maximal effects at a concentration of 4 micromolar. Neither vanadate nor azide inhibited enzyme activity. The purified ATPase was stimulated by Cl(-) and preferred Mg-ATP as substrate. Analysis of frations from the sucrose gradient by sodium dodecyl sulfate-polyacrylamide gel electrophoresis led to the identification of two major polypeptides at 72,000 and 62,000 daltons which were best correlated with ATPase activity. Several minor bands also appeared to copurify with enzyme activity, but were less consistent. Radiation inactivation experiments with intact membranes indicated that the functional molecular size of the tonoplast ATPase was nearly 400,000 daltons. This suggests that the ATPase is composed of several polypeptides, possibly including the 72,000- and 62,000-dalton proteins.
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PMID:Partial purification of a tonoplast ATPase from corn coleoptiles. 1666 39

Permeation of seven lanthanides (Ln) and thorium through a supported liquid membrane containing di-(n- octyl)phosphoric (DOPA) or di-(n-pentyl)phosphoric (DPPA) acid as a carrier has been studied as a function of the chemical composition of the system. The results have been compared with a previous study in which di-(2-ethylhexyl)phosphoric acid was used. Metal cations were transported from feed solutions of pH 1.1-4.8 (HNO(3)) into strip solutions of 0.015-0.1 mol l(-1) nitric acid. The ionic strength was kept constant at 0.1 mol l(-1) (HNO(3), KNO(3)). The initial lanthanide concentration and carrier concentration in the liquid membrane were varied from 0.5 to 500 mumol l(-1) and from 0.01 to 0.5 mol l(-1) respectively. To describe the mass transfer of metal cations, permeability coefficients have been determined by inductively-coupled plasma atomic emission spectroscopy or by on-line flow-injection analysis of metal concentrations in strip or feed solution. Probably as the result of a higher solubility of the carrier in aqueous media, transport of Ln with DPPA was not observed. By using DOPA, La, Ce, Pr, and Nd permeated through the membrane while transport of heavier Ln was partly or totally suppressed. This enables these four Ln (separation factor alpha = 3.0 for Nd and Sm) to be separated from the others. Furthermore, at a very low acidity gradient, only La (III) is transported over the membrane (alpha >/= 3.4 for La, Ce and next Ln). The seven elements from La to Tb can be separated from Th(IV) because no evidence of its permeation through the membrane was found under the conditions of Ln transport. In contrast to previous studies on Ln transport with dialkylphosphoric acid carrier, the possibility of participation of species other than Ln(AHA)(3) in the transport has been discussed. The decrease of permeability observed at higher Ln concentrations and higher pH of the feed solution has been explained as the result of formation of species, e.g. polymeric ones, that are unable to permeate through the membrane.
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PMID:Dialkylphosphoric acids as carriers in separation of lanthanides and thorium on supported liquid membranes. 1896 31