共查询到20条相似文献,搜索用时 31 毫秒
1.
Interactions of ganglioside GM1 with human and fetal calf sera. Formation of ganglioside-serum albumin complexes 总被引:1,自引:0,他引:1
B Venerando S Roberti S Sonnino A Fiorilli G Tettamanti 《Biochimica et biophysica acta》1982,692(1):18-26
The interactions of ganglioside GM1 with human and fetal calf sera were studied, the following main results being obtained: (a) GM1, upon incubation with both sera gave origin to two GM1-protein complexes, which also occurred after interaction of GM1 with the albumin fractions prepared from the same sera. Instead no complex formation occurred using the albumin-free fractions. Therefore GM1 appeared to specifically bind serum albumin and to form GM1-albumin complexes. (b) GM1 binding to serum albumin started at ganglioside concentrations surely micellar (above 10(-6) M), was time and concentration dependent, and resulted in a relevant degree of GM1 complexation (up to 80% of total GM1 in human serum and up to 18% in fetal calf serum). (c) the binding kinetics appeared, in both serum and the correspondent albumin fraction, to be biphasic: in the first phase, occurring till about 2 . 10(-4) M GM1, the ratio between bound and total GM1 increased linearly with increasing GM1 concentration; in the second phase, occurring above 2 . 10(-4) M, the ratio remained practically constant. After these findings it should be expected that GM1, when present in serum containing systems, forms complexes with albumin. This should be approximately considered when studying the effects of exogeneous GM1 in in vivo and in vitro (tissue cultures) systems. 相似文献
2.
The enzymatic basis for the differences in hepatic ganglioside patterns in the mouse strains C57Bl/6 and Swiss White (SW) was investigated. SW has a “Swiss-type” ganglioside profile, expressing GM1 ? and GD1a ? in addition to GM2 ? as major hepatic gangliosides, whereas C57Bl/6 shows a “GM2-type” profile, expressing only GM2 ? as the major hepatic ganglioside. The enzyme UDP-galactose:GM2 ganglioside galactosyltransferase (GM2-GalT), which catalyzes the synthesis of GM1 ganglioside, showed a four- to fivefold elevation in intact and solubilized liver Golgi membrane fractions of the SW strain compared to C57Bl/6. Crosses between C57Bl/6 and SW produced an F1 generation with a hepatic ganglioside and enzymatic phenotype intermediate between those of the two parental strains. All three genotypic groups show two forms of the Golgi apparatus enzyme with isoelectric points of 6.5–6.8 and 8.3–9.0. The simplest mode of action of genes which control the enzymatic phenotype that would be consistent with these findings are one or two structural genes or one or two cis-regulatory genes affecting the rate of enzyme synthesis. 相似文献
3.
Gangliosides in the external surface of intact synaptosomes from rat brain cortex have been studied by oxidation of exposed galactose and galactosamine groups with galactose oxidase followed by reduction with labeled sodium borohydride. Purified synaptosomes were labeled, disrupted by osmotic shock, and the particulate components fractionated on diatrizoate to give four synaptosomal membrane fractions (A-D) and a mitochondrial pellet (E). Fractions A and B represent synaptosomal plasma membranes. When intact synaptosomes were labeled, the major portion of the total radioactivity incorporated into ganglioside fraction was found to be in G
M1
3
species. With isolated membrane fractions little selectivity was seen: (1) more label was present compared to intact synaptosomes, and (2) zones corresponding to GM2, GM1, GD1a, GD1b were the major gangliosides labeled. The results confirm the conclusion that membrane fractions A and B are derived from the exposed synaptosome surface and also show that GM1 is the major ganglioside species available for enzyme oxidation at the surface. 相似文献
4.
Gangliosides were isolated from human brain myelin, oligodendroglia, and neurons. Quantitative analysis revealed the following ganglioside contents: myelin, 2.0; neurons, 1.3; and oligodendroglia, 0.35 μg ganglioside sialic acid per mg protein. Myclin had a relatively simple ganglioside pattern with GM4 and GM1 as the predominant ganglioside species. The ganglioside pattern of oligodendroglia was quite complex and it resembled that of whole white matter rather than that of myelin. A high concentration of GM4 was found in oligodendroglial fractions in addition to GM1, GD1a, GD1b, and GT1b. The usually- minor brain gangliosides GM3, GM2, and GM3 were also enriched in oligodendroglia. The neuronal ganglioside pattern was generally similar to the pattern of whole gray matter. Both neurons and whole gray matter contained very low amounts of GM4. These results indicate that GM4 is specifically localized in myelin and oligodendroglia of the CNS. Evidence is also presented that myelin, but not oligodendroglia, is the major reservoir of human white matter GM1 and GM4. 相似文献
5.
H. Dreyfus P. F. Urban P. Bosch S. Edel-Harth G. Rebel P. Mandel 《Journal of neurochemistry》1974,22(6):1073-1078
—The gangliosides of the whole calf retina and the rod outer segments have been analysed. This has been done in two functional states: before and after stimulation by light. After exposure to light no statistically significant change in the gangliosides of the whole retina was observed, but a 40 per cent increase in concentration was found in the rod outer segments. This difference was apparent only when using the same batch of rod outer segments. The major ganglioside in the whole calf retina is GD3 which accounts for 46 per cent of the total. Three other gangliosides GD1a, GD1b and GT1 are quantitatively important, each being between 12 and 16 per cent. GQ1, GM1, and GM3 are minor constituents. In contrast to the chicken retina, GM2 was not detected. The ganglioside N-acetylneuraminic acid of the rod outer segments accounts for only 1 per cent of the gangliosides of the whole retina. The composition of the gangliosides in the rod outer segments is essentially the same as that of the whole retina. No difference in the relative proportion of the gangliosides of either the rod outer segments or the whole retina was observed after exposure to light. 相似文献
6.
Prostaglandin generation by human peripheral blood mononuclear cells is enhanced during co-culture with human thyroid cells. The objective of the present study was to determine the influence of various sera on this process. Human thyroid adenoma cell monolayers were cultured with normal human peripheral blood mononuclear cells for three days in the presence of a variety of sera, or serum fractions. Prostaglandin E (PGE) in the medium was measured by bioassay or by radioimmunoassay. Significantly more PGE was generated in cultures containing fetal calf serum than in those containing human serum. This difference was not abolished by dialysis of the human serum. When the 50% (NH4) 2SO4 precipitate of the serum was used, PGE generation was similar to that in fetal calf serum, indicating the presence of an inhibitory factor in human serum. The degree of this inhibitory activity was similar in autologous and heterologous human serum, as well as in normal subjects and patients with Graves' disease. Gel filtration and ion-exchange chomatography of human serum showed the inhibitor to co-migrate with albumin. Evidence presented suggests that the inhibitor is not albumin itself but is, instead, a factor tightly bound to albumin. Inhibitory activity was also found in rabbit, goat, rat and cow serum. Prostaglandins are potent modulators of immune-cell function. These data indicate that this process may be modulated by a factor in mammalian serum. The relative absence of this factor in fetal serum may have important implications in regard to the profound changes which occur in the immune system after birth. 相似文献
7.
Andreas Janshoff Claudia Steinem Manfred Sieber A. el Bayâ Marcus Alexander Schmidt H.-J. Galla 《European biophysics journal : EBJ》1997,26(3):261-270
The binding of cholera toxin, tetanus toxin and pertussis toxin to ganglioside containing solid supported membranes has been
investigated by quartz crystal microbalance measurements. The bilayers were prepared by fusion of phospholipid-vesicles on
a hydrophobic monolayer of octanethiol chemisorbed on one gold electrode placed on the 5 MHz AT-cut quartz crystal. The ability
of the gangliosides GM1, GM3, GD1a, GD1b, GT1b and asialo-GM1 to act as suitable receptors for the different toxins was tested by measuring the changes of quartz resonance frequencies.
To obtain the binding constants of each ligand-receptor-couple Langmuir-isotherms were successfully fitted to the experimental
adsorption isotherms. Cholera toxin shows a high affinity for GM1 (Ka = 1.8 ⋅ 108M–1), a lower one for asialo-GM1 (Ka = 1.0 ⋅ 107 M–1) and no affinity for GM3. The C-fragment of tetanus toxin binds to ganglioside GD1a, GD1b and GT1b containing membranes with similar affinity (Ka∼106 M–1), while no binding was observed with GM3. Pertussis toxin binds to membranes containing the ganglioside GD1a with a binding constant of Ka = 1.6 ⋅ 106 M–1, but only if large amounts (40 mol%) of GD1a are present. The maximum frequency shift caused by the protein adsorption depends strongly on the molecular structure of
the receptor. This is clearly demonstrated by an observed maximum frequency decrease of 99 Hz for the adsorption of the C-fragment
of tetanus toxin to GD1b. In contrast to this large frequency decrease, which was unexpectedly high with respect to Sauerbrey's equation, implying
pure mass loading, a maximum shift of only 28 Hz was detected after adsorption of the C-fragment of tetanus toxin to GD1a.
Received: 14 January 1997 / Accepted: 15 April 1997 相似文献
8.
Shedding of immunosuppressive gangliosides is an important characteristic of both experimental and human tumors. Using a medulloblastoma cell line, Daoy, with a very high ganglioside expression (141 ± 13 nmol/108cells) and a well-characterized ganglioside complement, we have now studied ganglioside shedding by human brain tumor cells. Shedding of gangliosides, quantified by metabolic radiolabeling, was significant (169 pmol/108cells/h) and was generalized with respect to the major ganglioside carbohydrate structures (GM2, GM3, and GD1a). For each ganglioside, however, shedding was selective for ceramide structures containing shorter fatty acyl chains. Rapid and ceramide-selective shedding was confirmed in two additional human medulloblastoma cell lines, D341 Med and D283 Med (112 and 59 pmol/108cells/h). Significant ganglioside shedding is therefore a common characteristic of human medulloblastoma cells and may influence the biological behavior of this tumor, in view of immunosuppressive and other biological properties of shed gangliosides. 相似文献
9.
The synthesis of complexes of Li(I), K(I), Mg(II), Ca(II) and Ba(II) with guanosine in basic non aqueous solutions is described. The complexes were of two types: (1) complexes having the general formula, M(Guo)nXm·YH2O·ZC2H5OH, where M = Mg(II), Ca(II), Ba(II) and Li(I), n = 1,2,4, X = Cl?, Br?, NO3?, ClO4? and OH?, m = 1,2, Y = 0?6 and X = 0?2, and (2) complexes with the general formula, M(GuoH-1)(OH)n?1·YH2O, where M = K(I), Ca(Il) and Ba(II), GuoH-1 =Ionized guanosine at N1, n = 1,2 and Y = 1?3. The complexes are characterized by their proton nuclear magnetic resonance (1H NMR) and Fourier transform infrared (FT-IR) spectra. The FT-IR and 1H NMR data of the non ionized nucleoside complexes suggest that the metal binding is through the N7-site of guanine and that the anion (X) is hydrogen bonded to N1H and NH2 groups. In the N1-ionized guanosine complexes the metal binding is via the O6? of guanine. All the complexes formed exhibited a transition of the sugar conformation from C2′-endo/anti in the free nucleoside to C3′-endo/anti in the metal complexes. 相似文献
10.
Formation and turnover of myelin ganglioside 总被引:7,自引:6,他引:1
K Suzuki 《Journal of neurochemistry》1970,17(2):209-213
—In young adult rats, the formation and turnover of GM1-ganglioside in myelin were compared with the formation and turnover of GM1-ganglioside in whole brain and of total lipids in whole brain and myelin, after injection of d-[1-14C]glucosamine. During the first 24 hr after injection, the specific activity of GM1-ganglioside in myelin was less than 25 per cent of that of GM1-ganglioside in whole brain. The specific activity of ganglioside in whole brain was maximal at 24 hr and then declined steadily during the next 3 months, whereas the specific activity of GM1-ganglioside in myelin continued to increase and did not reach a peak until about one month after injection, by which time its specific activity had increased five-fold. Consequently, the specific activity of GM1-ganglioside in myelin was 50 per cent higher than ganglioside in whole brain after one month. These differences in the formation and turnover of GM1-ganglioside in myelin and of whole brain are similar to those of other lipids of myelin and of whole brain, indicating that the metabolic activity of myelin ganglioside is similar to myelin lipids, but differs from whole brain lipids or whole brain gangliosides. These data provide additional evidence that ganglioside in myelin is an intrinsic constituent of the myelin sheath. GT1 (G1), GD1b, (G2), GD1a (G3), GM1 (G4), GM2 (G5), GM3 (G6). 相似文献
11.
Nina V Prokazova Irina A Mikhailenko Sergey N Preobrazhensky Vadim O Ivanov Sergey N Pokrovsky Natalia G Timofeeva Maria A Martinova Vadim S Repin Lev D Bergelson 《Glycoconjugate journal》1986,3(3):273-286
The role of gangliosides in the reception of low density lipoproteins (LDL) was studied using as targets mouse ascites hepatoma 22a (MAH) cells which bind LDL through a specific high affinity receptor. Low density lipoprotein binding and uptake by MAH cells decreased after brief treatment of the cells with neuraminidase to partially remove surface sialic acid residues. The LDL uptake capability of the neuraminidasetreated MAH cells was fully restored after incorporation of exogeneous GM1- and GD1a-gangliosides into the cell surface. In contrast, free (extracellular) gangliosides inhibited LDL uptake by native MAH cells. This inhibitory effect was seen at ganglioside concentrations corresponding to the ganglioside content of serum and was most pronounced with gangliosides whose sialic acids were linked to a terminal galactose residue (GM3, GD1a, GT1b) but was smaller or absent with gangliosides whose sialic acids were attached to an internal galactose (GM1, GM2). The binding of gangliosides to LDL was structure and concentration dependent, saturable and trypsin sensitive. The LDL-ganglioside interaction was further investigated by steady state fluorescence spectroscopy. Changes in the LDL fluorescence polarization were observed with as little as 0.01 M concentrations of the gangliosides. The magnitude and nature of the effect depended on the type of ganglioside. We conclude that the LDL surface possesses sites recognizing specific carbohydrate sequences of glycoconjugates and that changes in the cell surface concentrations of sialic acids significantly modulate the LDL uptake. It is postulated that shedding of gangliosides into the blood stream may be a factor involved in regulation of cholesterol homeostasis.Abbreviations MAH
mouse ascites hepatoma 22a
- LDL
low density lipoprotein
- ASM
anthrylvinyl-labeled sphingomyelin [N-12-(9-anthryl-trans-dodecanoyl-sphingosine-1-phosphocholine]
- RITC
rhodamine isothiocyanate. The designation of gangliosides follows the IUPAC-IUB recommendation [1]: GM3, II3NeuAc-LacCer, II3-N-acetylneuraminosyllactosylceramide
- GM2
II3-NeuAc-GgOse3Cer, II3-N-acetylneuraminosylgangliotriaosylceramide
- GM1
II3-NeuAc-GgOse4Cer, II3-N-acetylneuraminosylgangliotetraosylceramide
- GD1a, II3
IV3(NeuAc)2-GgOse4Cer, II3, IV3-di(N-acetylneuraminosyl)gangliotetraosylceramide
- GT1b
II3(NeuAc)2, IV3 NeuAc-GgOse4Cer, II3-di-N-acetylneuraminosyl, IV3-N-acetylneuraminosylgangliotetraosylceramide 相似文献
12.
A radioassay for the rapid determination of GM1, ganglioside concentration in small volumes of CSF from individual patients is described. The assay utilizes the high-affinity interaction between cholera enterotoxin and GM1 ganglioside. The lower detection limit of GM1 ganglioside by this radioassay under the described incubation conditions is 2.5 ng/ml. The radioassay-determined lumbar CSF GM1 ganglioside concentrations in a small group of patients with diverse neurologic disorders are presented. The radioassay GM1 ganglioside concentration is in good agreement with the GM1 ganglioside concentration determined, in one patient, by the tlc-densitometry technique. 相似文献
13.
Enrico Bertoli Massimo Masserini Sandro Sonnino Riccardo Ghidoni Benvenuto Cestaro Guido Tettamanti 《生物化学与生物物理学报:生物膜》1981,647(2):196-202
The influence of different gangliosides (GM1, GD1a, GT1b) on the fluidity and surface dynamics of phosphatidylcholine small unilamellar vesicles was studied by electron paramagnetic resonance. 5-and 16-nitroxystearic acid, sounding respectively the region close to the surface and that close to the hydrophobic core of the vesicle, were employed as spin-label probes. The signals released by 5-nitroxystearic acid showed that the presence of gangliosides reduced the mobility of the hydrocarbon chains around the probe. The effect increased by increasing ganglioside concentration, and diminished from GM1 to GD1a and GT1b. The decrease of membrane fluidity was also monitored by the 16-nitroxystearic acid probe. On addition of Ca2+ the fluidity of ganglioside-containing vesicles (as signalled by the 5-nitroxystearic acid probe) promptly decreased, thereafter returning slowly to the original value. It is suggested that gangliosides cause strong side-side head group interactions on the bilayer surface -between ganglioside oligosaccharide chains and between ganglioside and phosphatidylcholine polar portions - which lead the lipid chains to assembly in a more rigid fashion. The influence of Ca2+ is interpreted as due to lateral phase separation in the vesicle membrane. This phenomenon can be related to the formation or stabilization of ganglioside clusters on the vesicle surface. 相似文献
14.
Binding of Paeonol to Human Serum Albumin: A Hybrid Spectroscopic Approach and Conformational Study
下载免费PDF全文
![点击此处可从《Journal of biochemical and molecular toxicology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Juan Wang 《Journal of biochemical and molecular toxicology》2015,29(5):213-220
The purpose of this study was to elucidate the binding of paeonol to human serum albumin (HSA) through spectroscopic methods. The fluorescence quenching of HSA by paeonol was a result of the formation of the HSA–paeonol complex with low binding affinity (K = 4.45 × 103 M?1 at 298 K). Thermodynamic parameters (ΔG○ = –2.08 × 104 J·mol?1, ΔS○ = 77.9 J·mol?1·K?1, ΔH○ = 2.41 × 103 J·mol?1, kq = 9.67 × 1012 M?1·s?1) revealed that paeonol mainly binds HSA through hydrophobic force following a static quenching mode. The binding distance was estimated to be 1.91 nm by fluorescence resonant energy transfer. The conformation of HSA was changed and aggregates were formed in the presence of paeonol, revealed by synchronous fluorescence, circular dichroism, Fourier transform infrared spectroscopy, three‐dimensional fluorescence spectroscopy, and resonance light scattering results. 相似文献
15.
Reinhard Hilbig Harald Rösner Gertraude Merz Kordula Segler-Stahl Hinrich Rahmann 《Development genes and evolution》1982,191(4):281-284
Summary Developmental profiles of 11 gangliosides, concentration of lipid- and glycoprotein-bound sialic acid, and activity of AChE of the rat and mouse cerebral cortex were followed from the 7th day of gestation to the 21st postnatal day.There are three main changes in ganglioside concentration, which are similar in both species. The first occurs from gestation day 10 until birth: parallel to decreased proliferation, cell migration, and neuroblast differentiation, GM3 and GD3 in mouse cortex and GD3 in the rat's decreases in favor of GQ1b, GT1b, and GD1a.The second occurs from birth until the first postnatal week: Parallel to increased growth and arborization of dendrites and axons as well as synaptogenesis in rats and mice, there is a two-fold rise of GD1a, whereas GQ1b and GT1b remain on a nearly constant level. Concomitantly, GM3 and GD3 decreases. The third period of ganglioside changes starts in the second postnatal week, parallel to onset of myelination, and is characterized by an increase of GM1 in parallel with a decrease of the polysialogangliosides GT1b and GQ1b. 相似文献
16.
《Biochimica et Biophysica Acta (BBA)/Molecular Cell Research》1988,968(2):167-171
Platelet interaction with gangliosides GD3, GM3, GM1, GD1a and GT1b has been investigated. These gangliosides were previously identified in the vessel wall and ganglioside GD3 was found to accumulate selectively in the intima of atherosclerotic vessels. Gangliosides were adsorbed to plastic and incubated with 51Cr-labeled platelets. The adhesion of gel-filtered platelets to ganglioside GD3 was 3–4-times higher than to other immobilized gangliosides and to albumin-treated plastic. As was shown by scanning electron microscopy, GD3 stimulated intensive spreading of adherent platelets and formation of surface-bound aggregates, while only single unspread platelets were present on the surfaces coated with other gangliosides. GD3 isolated from milk and from human aorta possess the same stimulating activity. Platelet adhesion to GD3 decreased significantly in the presence of the stable prostacyclin analogue, carbacyclin. 相似文献
17.
Guiliano Gazzotti Sandro Sonnino Riccardo Ghidoni Paolo Orlando Guido Tettamanti 《Glycoconjugate journal》1984,1(2):111-121
Gangliosides GM2, GM1 and GD1b were radiolabelled at C-6 of the terminal galactose orN-acetylgalactosamine by the galactose oxidase/[3H]NaBH4 method; gangliosides GM2, GM1, Fuc-GM1 and GD1a were radiolabelled at C-3 of the long chain base by the 2,3-dichloro-5,6-dicyanobenzoquinone/[3H]NaBH4 method.By application of an original HPLC procedure, eight different molecular species were prepared from each labelled ganglioside. Each of these species was characterized by the presence of one of the following long chain bases:erythro C18 sphingosine,threo C18 sphingosine,erythro C18 sphinganine,threo C18 sphinganine,erythro C20 sphingosine,threo C20 sphingosine,erythro C20 sphinganine andthreo C20 sphinganine.From GD1b only the species containing theerythro forms of long chain bases were obtained.The individual molecular species were more than 99% homogeneous and had a radiopurity better than 99%. The molecular species of the same ganglioside, radiolabelled at C-3 of the long chain base, had identical specific radioactivity, namely 1.17, 1.25, 0.85 and 1.28 Ci/mmol for GM2, GM1, Fuc-GM1 and GD1a respectively. The molecular species of the same ganglioside, radiolabelled at C-6 of terminal galactose orN-acetylgalactosamine, had similar specific radioactivity, namely 1.34–1.40, 1.44–1.51, 1.37–1.44 Ci/mmol for GM2, GM1 and GD1b respectively. 相似文献
18.
19.
《Biochimica et Biophysica Acta (BBA)/Lipids and Lipid Metabolism》1986,875(2):220-226
The ganglioside and neutral glycosphingolipid composition of fetal and adult sheep small intestinal mucosa were characterized and compared. Mono- and tetrahexosylceramide were the major neutral glycolipids of both fetal and adult tissue. Fetal mucosa, however, possessed a higher content of monohexosylceramide than its adult counterpart. Similarly, GD1a, GM3 and GM2 were found to be the principal gangliosides in fetal and adult tissue. Adult intestinal mucosa possessed significant amounts of GT1a not present in fetal tissue. Analysis of the hydroxy and nonhydroxy fatty acids as well as the long-chain bases of the major glycosphingolipids revealed differences between these lipophilic components of glycolipids in fetal and adult intestinal mucosa. The results, therefore, indicate that both quantitative and qualitative differences in glycosphingolipid composition exist between fetal and adult sheep small intestinal mucosa. 相似文献
20.
We investigated the in vitro stimulatory effect of ganglioside (GM3, GD1a, GD1b, GT1b, or GQ1b)-containing liposomes on human immune cells. The effect of ganglioside-containing liposomes on the concentration of cytoplasmic free calcium ions ([Ca2+]1) in human immunocytes was examined using the confocal laser fluorescence microscopic method. The GD1a- and GT1b-containing liposomes significantly increased [Ca2+]1 of human T lymphocytes compared with the GM3-, GD1b- and GQ1b-containing ones. The response of CD8+ and CD4+ cells was significantly higher than that of CD20+ cells. Our results show that the increase in [Ca2+]i may be caused by not the number of sialic acids contained in the gangliosides but the conformation of the sialic acid moiety to protrude exteriorly from the liposomal membrane surface, and that a sort of receptor recognizing the sialic acid moiety exists on human T lymphocytes (both CD8+ and CD4+ cells), which may be involved in the activation of the cells. The present results are almost the same as those obtained for the rat T lymphocyte system previously reported. This clearly confirms that a sort of ganglioside surely stimulates T lymphocytes directly, which is not species-specific but conserved in humans and rats among animal species. 相似文献