The relationship between the mitogenic lectin PNA [peanut agglutinin] and other mitogenic and non-mitogenic lectins was investigated. PNA labeled with 125I bound equally well to T [thymus derived] and B [bone marrow d...
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The relationship between the mitogenic lectin PNA [peanut agglutinin] and other mitogenic and non-mitogenic lectins was investigated. PNA labeled with 125I bound equally well to T [thymus derived] and B [bone marrow derived] lymphocytes, after neuraminidase treatment, with 3.88 .times. 106 and 3.73 .times. 106 binding sites, respectively. Only the T cell fraction was stimulated and only after neuraminidase treatment. Preincubation of neuraminidase-treated cells with non-mitogenic lectins and antiserum, which appeared to bind to the same receptor as PNA, enhanced the latter''s stimulatory properties. Capping and co-capping techniques were used to examine the topology of lectin receptors on the lymphocyte surface. The receptor glycoprotein for the mitogenic PNA lectin was distinct from that possessing the Con A [concanavalin A] and PHA [phytohemagglutinin] receptors, and that possessing the receptor for the non-mitogenic lectin from Helix pomatia.
Let p , q be arbitrary parameter sets, and let H be a Hilbert space. We say that x = ( x i ) iϵq , x i ϵ H , is a bounded operator-forming vector (ϵ H f q ) if the Gram matrix 〈 x , x 〉 = [( x i , x j )] iϵq , jϵq i...
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Let p , q be arbitrary parameter sets, and let H be a Hilbert space. We say that x = ( x i ) iϵq , x i ϵ H , is a bounded operator-forming vector (ϵ H f q ) if the Gram matrix 〈 x , x 〉 = [( x i , x j )] iϵq , jϵq is the matrix of a bounded (necessarily ≥ 0) operator on l q 2 , the Hilbert space of square-summable complex-valued functions on q . Let A be p × q , i.e., let A be a linear operator from l q 2 to l p 2 . Then exists a linear operator Ǎ from (the Banach space) H f q to H f p on D (A) = {x:x ϵ H f q , A〈x, x〉 1 2 is p × q bounded on l q 2 } such that y = Ǎx satisfies y j ϵ σ ( x ) = {space spanned by the x i }, 〈 y , x 〉 = A 〈 x , x 〉 and 〈y, y〉 = A〈x, x〉 1 2 (A〈x, x〉 1 2 ) ∗ . This is a generalization of our earlier [ J. Multivariate Anal. 4 (1974), 166–209; 6 (1976), 538–571] results for the case of a spectral measure concentrated on one point. We apply these tools to investigate q-variate wide-sense Markov processes.
Penicillium charlesii contains a nucleoside diphosphosugar:NAD 2-hexosyl oxidoreductase that oxidizes UDPgalactose (UDP-Galp), ADPribose [1,2] and UDPglucose (UDP-Glc). Dithiothreitol, NAD and 0.25 M NaCl but not nucl...
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Penicillium charlesii contains a nucleoside diphosphosugar:NAD 2-hexosyl oxidoreductase that oxidizes UDPgalactose (UDP-Galp), ADPribose [1,2] and UDPglucose (UDP-Glc). Dithiothreitol, NAD and 0.25 M NaCl but not nucleoside diphosphates stabilize the enzyme activity. The enzyme was purified and separated on polyacrylamide disc gels by electrophoresis into 1 major and 8 minor bands of protein. Oxidoreductase activity was located in the major and 3 of the minor bands of protein. Each of these proteins catalyze the oxidation of UDPGalp, ADPribose and UDP-Glc.
Preliminary testing procedures for the two means problem traditionally employ the pooled variance t -statistic. In this paper we show that bias of the t -statistic under conditions of heterogeneity of variance may be ...
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Preliminary testing procedures for the two means problem traditionally employ the pooled variance t -statistic. In this paper we show that bias of the t -statistic under conditions of heterogeneity of variance may be increased if use of the t -statistic is conditional on an affirmative f -test. for this reason we conclude that use of the t -statistic in preliminary testing procedures is inappropriate.
A solid-phase haptenic immunogen, DNP-PAB [dinitrophenyl-polyacrylamide beads], was prepared through the reaction of the hydrazide derivative of PB with dinitrobenzenesulfonic acid. A new method was presented for quan...
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A solid-phase haptenic immunogen, DNP-PAB [dinitrophenyl-polyacrylamide beads], was prepared through the reaction of the hydrazide derivative of PB with dinitrobenzenesulfonic acid. A new method was presented for quantifying the number of haptenic groups. DNP-PAB is very immunogenic for dissociated mouse spleen cells in culture, and the anti-hapten response is highly specific.
The ultrastructure of the somatic muscle cells of the adult and 6 developmental stages of M. muris were studied. In all stages the cells consisted of a contractile region containing myofibrils separated by dense bands...
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The ultrastructure of the somatic muscle cells of the adult and 6 developmental stages of M. muris were studied. In all stages the cells consisted of a contractile region containing myofibrils separated by dense bands and a noncontractile region with nuclei, mitochondria, glycogen, lipid droplets and vesicles. Two sizes of myofilaments were present. The dense band contained T[transverse]-tubules and sarcoplasmic reticulum, and, in more advanced stages, support filaments, glycogen and dense bodies. The contractile region of the adult muscle cell consisted of several hundred irregularly shaped myofibrils arranged in a random pattern. This pattern of myofibrils was defined as irregular-coelomyarian. The 3rd stage larva had a shallow-coelomyarian myofibril configuration, which changed to coelomyarian in the late 3rd stage through the addition of new myofibrils at the apical contractile border. In the 4th stage larvae, the subdivision of existing myofibrils changed the pattern to irregular-coelomyarian.
Chloroplasts [pea] inhibited by incubation with h-droxylamine in the light exhibit a low fluorescence yield upon illumination in the presence of dithionite sufficient to completely reduce the primary acceptor, Q. In t...
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Chloroplasts [pea] inhibited by incubation with h-droxylamine in the light exhibit a low fluorescence yield upon illumination in the presence of dithionite sufficient to completely reduce the primary acceptor, Q. In the absence of Mg ions, the fluorescence yield is the same as in control chloroplasts, suggesting that the reason for the low yield is a defect in the mechanism by which Mg2+ enhances the fluorescence. These chloroplasts were previously shown to contain only low potential (Em7.8 = +80 mV) cytochrome b-559. In Photosystem II particles, in heat-treated chloroplasts and in trypsin-digested chloroplasts, high potential cytochrome b-559 is absent and the variable fluorescence yield is again low. Peas grown under intermittent light contain only 1/5 of the content of high potential cytochrome b-559 seen in fully greened plants, yet show high rates of water to methyl viologen electron transport. Aquisition of the high potential cytochrome b-559 accompanies synthesis of chlorophyll b, the onset of Mg-stimulated fluorescence and an increased variable yield offluorescence. A similar correlation was seen during greening of dark-grown barley. Apparently the high potential state of cytochrome b-559 is due to the same membrane properties which allow cation enhanced variable fluorescence, so that the presence of low potential cytochrome b-559 is accompanied by a decrease in variable fluorescence yield.
The interaction of acetylcholine receptor [from the electric organ of Torpedo marmorata] and acetylcholinesterase [from the electric organ of Electrophorus electricus] with lipid monolayers was followed by measuring c...
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The interaction of acetylcholine receptor [from the electric organ of Torpedo marmorata] and acetylcholinesterase [from the electric organ of Electrophorus electricus] with lipid monolayers was followed by measuring changes in surface pressure. When injected into the subphase of a lipid monolayer, the proteins caused increases in surface pressure from 5 to 10 dynes/cm, indicating a penetration of protein into the monolayer. At pH values below the isoelectric point of the proteins the incorporation was improved. The same was observed when Ca2+ (2 mM) was added. The presence of the enzyme in the mixed film was demonstrated by using diiso[3H]propyl fluorophosphate-labeled acetylcholinesterase and by measuring enzyme activity. Acetylcholine receptor was demonstrated in the mixed film by using a complex made of the receptor and .alpha.-[3H]neurotoxin.
A novel method for the determination of equilibrium constants for reversible reactions is described. The method is based on the measurement of initial velocities of isotope transfer for a given substrate-product pair ...
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A novel method for the determination of equilibrium constants for reversible reactions is described. The method is based on the measurement of initial velocities of isotope transfer for a given substrate-product pair of the forward and reverse reactions as a function of the mass action of reactants. The reciprocal values of these initial velocities are plotted against the mass action ratios of reactants. The observed Keq is the abscissa of the intersection point of these reciprocal plots, i.e., the mass action ratio at which the initial velocities of isotope transfer for both the forward and reverse reaction are identical, i.e., when isotope exchange is occurring. In this manner, an observed Keq of 0.2 was obtained from CTP:phosphorylcholine cytidyltransferase (CTP:cholinephosphate cytidyltransferase, EC 2.7.7.15) at ***. C and pH 7.5 under physiological conditions 1.0 mM free Mg2+ and 0.15 M salt concentration. A comparison of this value with the in vivo mass action of reactants calculated from published data indicates that this reaction is rate-limiting in the rat liver.
Incubation of reticulocyte lysates [rabbit] or isolated crude ribosomes with low levels of double-stranded RNA (0.1-10 ng/ml) induces the formation of an inhibitor of protein synthesis initiation similar to that obser...
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Incubation of reticulocyte lysates [rabbit] or isolated crude ribosomes with low levels of double-stranded RNA (0.1-10 ng/ml) induces the formation of an inhibitor of protein synthesis initiation similar to that observed in heme deficiency. The inhibitor is associated with a cyclic[c]AMP-independent protein kinase activity (ATP:protein phosphotransferase, EC 2.7.1.37) that phosphorylates the small polypeptide (38,000 daltons) of the eukaryotic initiation factor eIf-2. Activation of the inhibitor requires ATP in addition to double-stranded RNA and is accompanied by the phosphorylation of a 67,000 dalton polypeptide of unknown function. The inhibitor remains associated with the ribosomes during high-speed sedimentation. Once formed, the ribosome-associated inhibitor phosphorylates eIf-2 and inhibits protein synthesis in the absence of double-stranded RNA. Inhibition is prevented by exogenous eIf-2. The bound inhibitor can be solubilized by extraction with 0.5 M KCl. The soluble inhibitor preparation retains the ability to phosphorylate the small polypeptide of eIf-2 and to inhibit protein synthesis. Untreated crude ribosomes also contain cAMP-independent protein kinase activities that phosphorylate the middle polypeptide (49,000 daltons) of eIf-2 and several polypeptide subunits of eIf-3 (160,000, 125,000 and 65,000 daltons);these kinase activities are not affected by double-stranded RNA and do not inhibit protein synthesis.
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