Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027960 (mole)
 21,279 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Some alloys used in restorative dentistry may evoke an allergic contact stomatitis in certain persons. In order to protect patients from materials with undesired reactions, and considering corrosion characteristics of different alloys used, it is useful to devise an adequate patch test battery to include the most relevant metals. Dental alloys are composed of a combination of various metals. 12 different ions of frequent occurrence (Au3+, Pd2+, Zn2+, Mo6+, Sn2+, Ga3+, In3+, Co2+, Cr3+(6+), Ni2+, Fe2+(3+) and Si4+) were epicutaneously tested as the aqueous solution of the respective salt. The concentrations are given in g/100 ml and also in m.mole/l. The 12 different metal ion solutions were patch tested on patients in 3 groups: one group with a positive history of contact stomatitis (30 patients, group 1), one group with a positive history of contact dermatitis (16 patients, group 2), and a control group (17 persons, group 3). In contrast to the control group, a remarkable high percentage (11%) of positive skin reactions to Pd was found in groups 1 and 2. No allergic or irritant skin reactions were detected to Ga, Sn and Zn. No irritant reaction was observed at pH values as low as 1.5. In the case of SiCl4 (pH = 0.5), 41% positive irritant reactions were evoked. In the group with a positive history of contact dermatitis (group 1), a positive reaction was found more often (69%) than in the group with a positive history of contact stomatitis (30%) (group 2). The difference between these groups was mainly caused by reactions to Ni and Pd.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Test battery for metal allergy in dentistry. 370 61

The plasma membrane of bovine aortic endothelium was isolated, characterized, and found to contain at least four membrane-associated cytoskeletal proteins. Exposure of the plasma membranes to salt media (up to 1M KCl) resulted in the release of 30% of the total plasma membrane-associated proteins and extraction with 1% Triton X-100, 60%. At least four heavily glycosylated bands (185-, 165-, 150-, and 130,000 mol-wt) were evident. The Triton-insoluble pellet fraction contained several major polypeptides (30-, 43-, 58-, and 240,000 mol-wt), two of which were identified by immunoblotting as cytoplasmic actin (43,000 mol-st) and vimentin (58,000 mol-wt). Strikingly, vimentin and a 240,000 mol-wt polypeptide were routinely present in approximately a mole ratio of 4:1 in more than 60% of the plasma membrane preparations. We also report the presence of a 2.1-like and a 4.1-like protein associated with plasma membranes. The 2.1-like protein demonstrated similar solubilities and apparent molecular weight (210,000) as erythroid protein 2.1. Likewise, the endothelial 4.1-like protein exhibited similar solubilities and apparent molecular weight as erythroid protein 4.1. Immunofluorescence staining of fixed and permeabilized cultures with anti-2.1 antibodies showed a fibrillar pattern. In contrast, cells stained with anti-protein 4.1 were brightly fluorescent, bearing both a diffuse and punctate pattern. This paper presents several novel observations pertaining to the composition of bovine aortic endothelial cell plasma membranes, namely: the presence of two erythroid-like cytoskeletal polypeptides; the presence of vimentin and a 240,000 mol-wt polypeptide in a 4:1 mole ratio in more than 60% of the plasma membrane preparations and the co-elution in a 4:1 mol ratio with a protein perturbant; and the inability to release actin from the plasma membrane preparations, suggesting the association of actin with other molecules in the plasma membrane preparation.
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PMID:Isolation of bovine aortic endothelial cell plasma membranes: identification of membrane-associated cytoskeletal proteins. 373 85

Tropomyosin from equine platelets was reacted with N-(1-pyrenyl)iodoacetamide, a sulfhydryl-specific fluorescent reagent, to give an average extent of incorporation of 1.12 pyrene (Py) groups per platelet tropomyosin (P-TM) chain. The predominant site of reaction on P-TM was the penultimate COOH-terminal residue, Cys-246. The high proportion of the total emission that is due to pyrene ecximers and the pretransition observed in thermal denaturation of Py-P-TM point to a rather loose structure for the COOH-terminal amino acid residues of P-TM. The label on Cys-246 also reports on end-to-end overlap interactions that occur between two different tropomyosin molecules. Additions to a Py-P-TM solution at low ionic strength of unlabeled P-TM, rabbit cardiac tropomyosin (C-TM), or a carboxypeptidase A treated, nonpolymerizable derivative of C-TM all reduce the extent of excimer fluorescence from the sample. Addition of salt greatly reduces the effects of the unlabeled TM species on the Py-P-TM emission spectrum. Circular dichroism measurements indicate Py-P-TM still to be greater than 95% helical. However, analysis of excimer fluorescence levels in samples that contained a constant protein concentration but different mole ratios of labeled to unlabeled P-TM suggests that the bulky pyrene group may diminish the tendency of Py-P-TM to polymerize in an end-to-end manner.
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PMID:Excimer fluorescence of equine platelet tropomyosin labeled with N-(1-pyrenyl)iodoacetamide. 374 38

Light absorption and circular dichroism (CD) were recorded at 26 to 27 degrees C in dilute aqueous solutions (10(-4) M) of ferriprotoporphyrin IX (FP) in the presence of (+)-quinidine. In contrast to the appearance of relatively small and positive CD bands between pH 7 and 10, two bands of opposite sign, having unusually large molar ellipticities of the order of 10(6) deg X cm2 X dmol-1 FP were observed in the Soret region near 400 nm at pH 11.0-11.5. This unique complex A was formed only slowly over periods of hours or days at 26 degrees C. By lowering the pH of Complex A below 10, under certain conditions, an "enantiometric" mirror-image CD spectrum, with all bands having opposite sign to Complex A, was obtained in the range of 650 to 300 nm (Complex B), while the light-absorption spectra of Complexes A and B were similar. The formation of Complex A was inhibited at mole fractions of FP greater than 0.5. Also, this complex was not measurably formed at low salt concentrations. Ultracentrifugation measurements of the complex solutions indicated the presence of very high aggregates. Possible interpretations of the optical properties observed are based on interactions between FP molecules, which are assumed to be arrayed chirally within aggregates of FP with quinidine. A comparison between quinine and quinidine complexes of FP is presented.
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PMID:Optical properties of complexes of antimalarial drugs with ferriprotoporphyrin IX in aqueous medium. II. The system ferriprotoporphyrin IX-quinidine. 378 37

Treatment of S-acyl fatty acid synthase thioester hydrolase from the uropygial gland of Peking duck with pyrenebutylmethanephosphonofluoridate resulted in inactivation of the enzyme with covalent attachment of the pyrene derivative to the enzyme. One mole of the derivative was attached/mol of protein, most probably at the active serine. When avian fatty acid synthase was added to the modified thioesterase, the fluorescence anisotropy of the pyrene derivative increased dramatically. That this increase represented the functionally significant binding between the two proteins was suggested by the fact that increasing salt concentration resulted in concomitant loss in enzyme activity and fluorescence anisotropy. As the synthase concentration increased, anisotropy increased giving a saturation pattern. From a Scatchard plot analysis the association constant for the binding of the two proteins was calculated to be 10(6) M-1 and one-to-one stoichiometry was shown for this association. These results show that fluorescence anisotropy of the pyrene derivative attached to the thioesterase can be used to directly measure the binding of this enzyme to fatty acid synthase.
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PMID:Interaction of S-acyl fatty acid synthase thioester hydrolase with fatty acid synthase. Direct measurement of binding by fluorescence anisotropy. 396 77

The extrusion kinetics of two cruciforms derived from unrelated DNA sequences differ markedly. Kinetic barriers exist for both reactions, necessitating elevated temperatures before extrusion proceeds at measureable speeds, but the dependence upon temperature and ionic strength is quite different for the two sequences. One, the ColE1 inverted repeat, exhibits a remarkably great temperature dependence of reaction rate and is suppressed by moderate amounts of NaCl or MgCl2. In contrast, the other, a synthetic inverted repeat present in pIRbke8, shows more modest temperature dependence and has a requirement for the presence of salt, with optimal concentrations being 50 mM NaCl or 100 microM MgCl2. Under optimal conditions, cruciform extrusion rates are fast (t1/2 less than 60m) at 37 degrees C for both sequences at native superhelix densities. In 50 mM NaCl the pIRbke8 inverted repeat is characterised by an Arrhenius activation energy of 42.4 +/- 3.2 kcal mole -1. The differences in kinetic properties between the two sequences indicate that DNA base sequence is itself an important factor in determining cruciform kinetics, and possibly even in the selection of the mechanistic pathway.
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PMID:The kinetic properties of cruciform extrusion are determined by DNA base-sequence. 400 Sep 40

Partitioning of saturated fatty acids between discs of polyethylene film and aqueous buffer has been characterized and subsequently used to measure monomer activities of fatty acids in micellar solutions of bile salt. Partitioning of fatty acids between polyethylene and buffer achieved equilibrium in about 24-48 hr. Partition coefficients for fatty acids 10:0 and 16:0 were essentially independent of concentration, as expected for true partitioning. Experiments with various pH buffers showed that only the protonated form of fatty acids 12:0 and 16:0 participated in partitioning, and the midpoints of the partition coefficients vs. pH curves were 4.5-5.0 and 6.5-7.0, respectively. Experimentally determined partition coefficients at pH 7.4 ranged from 2.03 +/- 0.09 for 9:0 to 56,100 +/- 13,850 for 17:0. The addition of each methylene group increased the partition coefficient by a factor of about 3.75, corresponding to an incremental free energy change for each methylene group of -3433 J.mole(-1) (-820 cal.mole(-1)). Monomer activities of solutions of 14:0 and 16:0 dissolved in 20 mM taurodeoxycholate were linearly dependent on the total fatty acid concentration. 1 mM 14:0 and 16:0 in 20 mM taurodeoxycholate had monomer activities of 1.3 x 10(-5) M and 5.6 x 10(-7) M, respectively. Solutions prepared with a constant concentration ratio of fatty acid to taurodeoxycholate had essentially constant monomer activities between 8 and 20 mM taurodeoxycholate. These studies support the hypothesis that fatty acid interaction with bile acid micelles is similar to a phase distribution system, so that some measurable monomer activity of fatty acid exists in equilibrium with the mass of fatty acid contained in the micelle.
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PMID:Apparent monomer activity of saturated fatty acids im micellar bile salt solutions measured by a polyethylene partitioning system. 481 Dec 16

A thermophilic bacillus (minimal growth temperature 41 C, optimal 55 to 58 C, and maximal 65 C) was isolated from a manure pile. It is very similar to Bacillus stearothermophilus, but it differs in its inability to hydrolyze starch. The thermophilic isolate is a prototroph which grows in a minimal medium consisting of glucose, ammonium salt, phosphate buffer, and inorganic salts. At all temperatures studied (low to high), the same minimal nutritional requirements prevailed. The Arrhenius constant for growth was found to be 15,000 and 13,500 cal/mole in the minimal and rich media, respectively.
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PMID:Prototrophic thermophilic bacillus: isolation, properties, and kinetics of growth. 580 72

The interaction between bacteriophage R17 coat protein and its RNA binding site for translational repression was studied as an example of a sequence-specific RNA-protein interaction. A nitrocellulose filter retention assay is used to demonstrate equimolar binding between the coat protein and a synthetic 21 nucleotide RNA fragment. The Kd at 2 degrees C in a buffer containing 0.19 M salt is about 1 nM. The relatively weak ionic strength dependence of Ka and a delta H = -19 kcal/mole indicates that most of the binding free energy is due to non-electrostatic interactions. Since a variety of RNAs failed to compete with the 21 nucleotide fragment for coat protein binding, the interaction appears highly sequence specific. We have synthesized more than 30 different variants of the binding site sequence in order to identify the portions of the RNA molecule which are important for protein binding. Out of the five single stranded residues examined, four were essential for protein binding whereas the fifth could be replaced by any nucleotide. One variant was found to bind better than the wild type sequence. Substitution of nucleotides which disrupted the secondary structure of the binding fragment resulted in very poor binding to the protein. These data indicated that there are several points of contact between the RNA and the protein and the correct hairpin secondary structure of the RNA is essential for protein binding.
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PMID:Interaction of R17 coat protein with its RNA binding site for translational repression. 640 Nov 18

Cibacron Blue F3GA and its immobilized derivatives have been shown before to bind and inhibit nucleotide-dependent enzymes and, among them, myosin subfragment 1. Experiments have been carried out to examine the mechanism of the subfragment 1--dye interaction. Binding of subfragment 1 to immobilized dye (Affi-Gel Blue) does not involve the ATP binding site on myosin. Subfragment 1 hydrolyzes MgATP and CaATP while bound to the Affi-Gel Blue column. Inactivated subfragment 1, which contains [3H]ADP noncovalently trapped at the active site, binds and elutes from the Affi-Gel Blue column in the same manner as unmodified, active protein. Free Cibacron Blue inhibits the ATPase activity of subfragment 1. The inhibition is pH, salt, and time dependent. Complete inhibition correlates with the noncovalent binding of four to five dye molecules per mole of subfragment 1. Three to four of these dye molecules can be preferentially removed from subfragment 1 in the presence of 1 M KCl without relieving the inhibition. This inhibition, which can be traced to one dye molecule per subfragment 1, is reversible and is facilitated in the presence of MgADP and MgATP, suggesting that the dye does not bind at the active site of subfragment 1. Our observations are explained in terms of hydrophobic and electrostatic protein--dye interactions.
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PMID:Interaction of myosin subfragment 1 with Cibacron Blue F3GA. 645 18


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