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41.
Jan Holgersson Michael E Breimer Anita Jacobsson Lola Svensson Ami Ulfvin Bo E Samuelsson 《Glycoconjugate journal》1990,7(6):601-608
Total non-acid glycolipid fractions and total sodium dodecylsulphate (SDS) solubilized protein fractions were isolated from human thrombocytes obtained from single human donors having different blood group A1/A2 phenotypes. The blood group A glycolipid antigens were characterized by immunostaining of thin layer plates with different monoclonal anti-A antibodies. The glycoproteins carrying blood group A epitopes were identified by SDS-PAGE and Western blot analysis using a monoclonal anti-A antibody. Blood group A glycolipid antigens were found in both A1 and A2 thrombocytes but the A2 individuals expressed at least ten times less A glycolipids compared to the A1 individuals. Expression of A type 3/4 chain and small amounts of A type 1 chain glycolipids were seen in thrombocytes of both A1 and A2 individuals, while the type 2 chain A glycolipids appeared to be missing from the A2 thrombocytes. Blood group A reactive glycoproteins were only found in thrombocytes of A1 individuals and could not be detected in A2 individuals or a blood group O individual. The major blood group A glycoprotein were found as a double band migrating in the 130 kDa region.Abbreviations SDS
sodium dodecyl sulfate
- PAGE
polyacrylamide gel electrophoresis
- HPTLC
high performance thin layer chromatography
- CBB
Coomassie brilliant blue
- GVH
graft versus host
Part of this work was presented at the Xth International Symposium on Glycoconjugates, Jerusalem, Israel. September, 1989.In the short hand designation for glycolipids, the letter indicate blood group determinant, the first numeral, the number of sugar residues, and the second numeral, the type of carbohydrate chain. Thus, A-6-1 means a hexaglycosylceramide with a blood group A determinant based on the type 1 carbohydrate chain. 相似文献
42.
NAD+-linked primary and secondary alcohol dehydrogenase activity was detected in cell-free extracts of propane-grown Rhodococcus rhodochrous PNKb1. One enzyme was purified to homogeneity using a two-step procedure involving DEAE-cellulose and NAD-agarose chromatography and this exhibited both primary and secondary NAD+-linked alcohol dehydrogenase activity. The Mr of the enzyme was approximately 86,000 with subunits of Mr 42,000. The enzyme exhibited broad substrate specificity, oxidizing a range of short-chain primary and secondary alcohols (C2–C8) and representative cyclic and aromatic alcohols. The pH optimum was 10. At pH 6.5, in the presence of NADH, the enzyme catalysed the reduction of ketones to alcohols. The K
m values for propan-1-ol, propan-2-ol and NAD were 12 mM, 18 mM and 0.057 mM respectively. The enzyme was inhibited by metal-complexing agents and iodoacetate. The properties of this enzyme were compared with similar enzymes in the current literature, and were found to be significantly different from those thus far described. It is likely that this enzyme plays a major role in the assimilation of propane by R. rhodochrous PNKb1.Abbreviations HPLC
high performance liquid chromatography
- DEAE
diethyl amino ethyl
- IEF
isoelectrofocusing
- NTG
nitrosoguanidine
- SDS-PAGE
sodium dodecylsulphate polyacrylamide gel electrophoresis
- pI
isoelectric point 相似文献
43.
本实验在67只家兔身上分别观察了电解损毁孤束核(NTS)前后刺激腹迷走神经和内脏大神经中枢端对血压的影响,以及刺激这两种神经中枢端对 NTS 神经元放电活动的影响。结果表明:来自腹迷走神经和内脏大神经的感觉冲动不仅都可以投射至 NTS,而且这两种传入冲动在 NTS 还存在着会聚现象。一种传入神经的阈下刺激(背景刺激)可以削弱另一传入神经的血压效应,一种传入神经的(背景刺激)可以抑制另一种神经元引起的 NTS 神经元电活动。本文对这两种传入冲动之间存在的相互作用关系的可能机制及意义进行了讨论。 相似文献
44.
辣椒素引起脊髓P物质释放及其对血压的影响 总被引:5,自引:0,他引:5
为进一步研究脊髓 P 物质(SP)在调节心血管活动中的作用,在大鼠脊髓蛛网膜下腔注射(ith)辣淑素(cap),以刺激脊髓 SP 能神经末梢释放 SP,结果引起血浆去甲肾上腺素(NA)和肾上腺素(AD)含量增高,及具有剂量依赖性的动脉血压上升,心率升高。ith 具有高度特异性的 SP 受体拮抗剂或 SP 抗血清均可阻断 cap 引起的升压效应,免疫组化测定也观察到注入的cap 剂量越大,脊髓胸段 SP 样免疫阳性反应物的致密度越低,这些观察结果支持 cap 可以引起脊髓内 SP 的释放的说法。在第一颈段(C_1)横断脊髓后 ith cap 所引起的升压效应与完整动物 ith cap 的升压效应无显著差异。以上结果提示脊髓 SP 能神经末梢释放的 SP 可以通过交感肾上腺髓质系统引起心血管兴奋效应,SP 可能是引起交感节前神经元兴奋的神经递质。 相似文献
45.
大鼠缰核与下丘脑外侧区在调节心血管活动方面的机能联系 总被引:6,自引:0,他引:6
电刺激大鼠下丘脑外侧区(LH),动脉压明显升高,心率加快,在刺激电极同侧缰核(Hb)内微量注射盐酸利多卡因、电刺激LH引起的升压反应可被阻断38.9%,心率增快反应可被阻断44.4%,双侧Hb内微量注射盐酸利多卡因,电刺激LH引起的升压反应可被阻断40.7%,心率增快反应可被阻断41.2% ,单侧或双侧Hb内微量注射人工脑脊液均不能阻断电刺激LH引起的心血管反应。电刺激大鼠Hb,动脉压明显升高,心率无明显改变,在刺激电极同侧LH内微量注射盐酸利多卡因,电刺激Hb引起的升压反应可被阻断63.2%,双侧LH内微量注射盐酸利多卡因,电刺激Hb引起的升压反应可被阻断62.6%,单侧或双侧LH内微量注射人工脑脊液均不能阻断电刺激Hb引起的心血管反应。本实验提示Hb与LH在调节心血管活动方面有协同作用。 相似文献
46.
心房钠尿因子对麻醉家兔局部血流的影响 总被引:3,自引:2,他引:1
在42只麻醉家兔,观察了静脉注射心房肽Ⅱ(AtriopeptinⅡ,APⅡ)对局部血流量以及动脉内注射 AP Ⅱ 对局部血管阻力的影响。结果如下:(1)静脉注射 APⅡ(30μg/kg)5min后,平均动脉压(MAP)降低11.0±1.5mmHg(n=8,M±SE,下同),与溶剂对照组相比有明显差异(P相似文献
47.
The engineering considerations common to large scale chromatographic purification of proteins are reviewed. A discussion of the industrial chromatography fundamentals is followed by aspects which affect the scale of separation. The separation column geometry, the effect of the main operational parameters on separation performance, and the physical characteristics of column packing are treated. Throughout, the emphasis is on ion exchange and size exclusion techniques which together constitute the major portion of commercial chromatographic protein purifications. In all cases, the state of current technology is examined and areas in need of further development are noted.
The physico-chemical advances now underway in chromatographic separation of biopolymers would ensure a substantially enhanced role for these techniques in industrial production of products of new biotechnology. 相似文献
48.
Summary The adult rat lung cytoplasm contains some factors which markedly stimulate adenylate cyclase activity in plasma membranes (Nijjar, M. S. Biochim. Biophys. Acta 584:43–50, 1979). Adenylate cyclase activator (ACA) was purified from rat lungs by DEAE-cellulose chromatography, preparative isoelectric focusing and by repeated high-performance liquid chromatography on a Sepharogel TSK 2000SW column. The final preparation showed about 200 fold purification in ACA activity over the original lung supernatant, and appeared to be homogeneous on the basis of its migration into a single band on SDS-polyacrylamide gel electrophoresis, and co-elution of ACA activity with protein from a gel exclusion column. ACA is an acidic (pl 4.8 ± 0.1), heat labile, monomeric protein of 40000 ± 2000 dalton molecular weight, and does not resemble calmodulin. 相似文献
49.
Azotobacter vinelandii was grown diazotrophically in sucrose-limited chemostat cultures at either 12, 48, 108, 144 or 192 M dissolved oxygen. Steady state protein levels and growth yield coefficients (Y) on sucrose increased with increasing dilution rate (D). Specific rate of sucrose consumption (q) increased in direct proportion to D. Maintenance coefficients (m) extrapolated from plots of q versus D, as well as from plots of 1/Y versus 1/D exhibited a nonlinear relationship to the dissolved oxygen concentration. Constant maximal theoretical growth yield coefficients (Y
G) of 77.7 g cells per mol of sucrose consumed were extrapolated irrespective of differences in ambient oxygen concentration. For comparison, glucose-, as well as acetate-limited cultures were grown at 108 M oxygen. Fairly identical m- and Y
G-values, when based on mol of substrate-carbon with glucose and sucrose grown cells, indicated that both substrates were used with the same efficiency. However, acetate-limited cultures showed significantly lower m- and, at comparable, D, higher Y-values than cultures limited by either sucrose or glucose. Substrate concentrations (K
s) required for half-maximal growth rates on sucrose were not constant, they increased when the ambient oxygen concentration was raised and, at a given oxygen concentration, when D was decreased. Since biomass levels varied in linear proportion to K
s these results are interpreted in terms of variable substrate uptake activity of the culture.Abbreviations
D
dilution rate
-
K
s
substrate concentration required for half maximal growth rate
-
m
maintenance coefficient
-
q
specific rate of substrate consumption
-
Y
growth yield coefficient
-
Y
G
maximum theoretical growth yield coefficient 相似文献
50.
The fermentation of xylose by Thermoanaerobacter ethanolicus ATCC 31938 was studied in pH-controlled batch and continuous cultures. In batch culture, a dependency of growth rate, product yield, and product distribution upon xylose concentration was observed. With 27 mM xylose media, an ethanol yield of 1.3 mol ethanol/mol xylose (78% of maximum theoretical yield) was typically obtained. With the same media, xylose-limited growth in continuous culture could be achieved with a volumetric productivity of 0.50 g ethanol/liter h and a yield of 0.42 g ethanol/g xylose (1.37 mol ethanol/mol xylose). With extended operation of the chemostat, variation in xylose uptake and a decline in ethanol yield was seen. Instability with respect to fermentation performance was attributed to a selection for mutant populations with different metabolic characteristics. Ethanol production in these T. ethanolicus systems was compared with xylose-to-ethanol conversions of other organisms. Relative to the other systems, T. ethanolicus offers the advantages of a high ethanol yield at low xylose concentrations in batch culture and of a rapid growth rate. Its disadvantages include a lower ethanol yield at higher xylose concentrations in batch culture and an instability of fermentation characteristics in continuous culture. 相似文献