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871.
利用毛细管电泳分析唾液酸2-氨基吖啶酮(AMAC)衍生物方法, 可在飞摩尔水平分析糖蛋白中唾液酸. 重组人促红细胞生成素(rhu-EPO)、人尿胰蛋白酶抑制剂(hu-UTI)中唾液酸分析结果与文献值符合较好; 而牛α1-酸性糖蛋白(α1-AGP)分析结果与早期文献值相比, 存在一定差异, 并发现该糖蛋白中除含有5-N-乙酰氨基唾液酸(Neu5Ac)外, 还含数量与Neu5Ac相当的5-N-乙醇酰氨基唾液酸(Neu5Gc). 相似文献
872.
873.
874.
Mark R McCall Michael La Belle Trudy M Forte Ronald M Krauss Yoshikazu Takanami Diane L Tribble 《Biochimica et Biophysica Acta (BBA)/Molecular and Cell Biology of Lipids》1999,1437(1):23-36
Platelet-activating factor acetylhydrolase (PAF-AH) is transported by lipoproteins in plasma and is thought to possess both anti-inflammatory and anti-oxidative activity. It has been reported that PAF-AH is recovered primarily in small, dense LDL and HDL following ultracentrifugal separation of lipoproteins. In the present studies, we aimed to further define the distribution of PAF-AH among lipoprotein fractions and subfractions, and to determine whether these distributions are affected by the lipoprotein isolation strategy (FPLC versus sequential ultracentrifugation) and LDL particle distribution profile. When lipoproteins were isolated by FPLC, the bulk (~85%) of plasma PAF-AH activity was recovered within LDL-containing fractions, whereas with ultracentrifugation, there was a redistribution to HDL (which contained ~18% of the activity) and the d>1.21 g/ml fraction (which contained ~32%). Notably, re-ultracentrifugation of isolated LDL did not result in any further movement of PAF-AH to higher densities, suggesting the presence of dissociable and nondissociable forms of the enzyme on LDL. Differences were noted in the distribution of PAF-AH activity among LDL subfractions from subjects exhibiting the pattern A (primarily large, buoyant LDL) versus pattern B (primarily small, dense LDL) phenotype. In the latter group, there was a relative depletion of PAF-AH activity in subfractions in the intermediate to dense range (d=1.039–1.047 g/ml) with a corresponding increase in enzyme activity recovered within the d>1.21 g/ml ultracentrifugal fraction. Thus, there appears to be a greater proportion of the dissociable form of PAF-AH in pattern B subjects. In both populations, most of the nondissociable activity was recovered in a minor small, dense LDL subfraction. Based on conjugated dienes as a measure of lipid peroxidation, variations in PAF-AH activity appeared to contribute to variations in oxidative behavior among ultracentrifugally isolated LDL subfractions. The physiologic relevance of PAF-AH dissociability and the minor PAF-AH-enriched oxidation-resistant LDL subpopulation remains to be determined. 相似文献
875.
利用生化及分子标记确定长穗偃麦草(Elytrigia elongatum, EE. 2n=14)染色体与小麦染色体的部分同源性 总被引:2,自引:1,他引:1
利用限制性片段长度多态性(RFLP)及等电聚焦(IEF)技术确定普通小麦中国春-二倍体长穗僵麦草7个异附加系所附加的外源染色体与小麦染色体的部分同源性,共有8个生化标记,13个RFLP标记在亲本间揭示了多态性。结果表明:长穗堰麦草的IE、2E、3E、4E、 5E、6E、7E 7条染色体分别与小麦染色体的 1、2、3、4、5、6、7 7个部分同源群具有部分同源关系,堰麦草的IE与7E、5E与7E染色体间可能发生过重排。同时,研究还分别将Est-E5、Est-E8位点定位于3EL,Per-E1定位于7E, Per-E4定位于5E,β-Amy-E1定位于4EL染色体,并进一步将α-Amy-E1位点定位于6E染色体长臂上。 相似文献
876.
Wu Bao-gan 《植物学报(英文版)》1989,31(11)
The isozymes of superoxide dismutase (SOD) in leaves of wheat and peanut were investigated and identified by isoelectric focusing gel electrophoresis. The total four bands were found in wheat leaves, among them the band with the highest mobility was proved to be the chloroplastic SOD, the others with intermediate mobilities were probably cytoplasmic SODs. It was observed that there was apparent difference between patterns of SOD isozymes from leaves of wild and cultivated peanut. Leaves of wild peanut contain three different types of SOD isozyme (band A, band B and band C). Band A and B were cyanide-sensitive, hence they should be Cu-Zn-SOD. Band C was cyanide- insensitive and might be Mn-SOD located in mitochondria. The major part of SOD activity in cultivated peanut leaves was concentrated in chloroplasts, and it was cyanide-sensitive. The experiments of SOD activity inhibition by KCN showed that leaves of cultivated peanut contained more Cu-Zn-SOD. On the contrary, the percentage of non-Cu-Zn-SOD was highter in wild species than in cultivated. The PI values of distinct bands were determined and the significance of this study for the further evaluation of resistance of peanut plant is discussed. 相似文献
877.
黑线姬鼠华北亚种与长江亚种几项生化指标的比较观察 总被引:4,自引:3,他引:1
黑线姬鼠(Apodemus agrarius Pallas)在我国分布广泛,是大部分地区的主要农田害鼠,它传播多种疾病,是流行性出血热病毒的主要携带者。国内外学者对我国黑线姬鼠的分类、分布、数量变动、生活习性等进行过一些研究,但对黑线姬鼠许多生化指标的研究尚未见报道。 相似文献
878.
Induction of polyphenol oxidase in germinating wheat seeds 总被引:1,自引:0,他引:1
A 50- and 100-fold increase in the o-diphenolase activity was observed respectively in excised coleoptiles and roots of wheat seedlings after germination for 4–5 days. This increased activity was associated with the appearance of several new multiple forms of o-diphenolase on acrylamide gels. The embryo-less half-seeds dissected from seedlings, however, revealed only a three-fold increase in o-diphenolase activity, without any alteration in the pattern of multiple forms. Cycloheximide substantially inhibited the activity and appearance of multiple forms of o-diphenolase, whereas actinomycin D failed to bring about a similar response. Protein synthesis was probably necessary for the formation of new multiple forms. Unlike o-diphenolase activity which was present in all parts of the seedling, the monophenolase activity was confined to the embryo-less endosperm. A 5–7-fold increase in monophenolase activity was observed in the embryo-less half-seed dissected from the seedling. A single broad band of monophenolase developed on acrylamide gels. This persisted during the early period of seed germination without addition of new multiple forms. No inhibition of monophenolase activity was observed in seeds treated with cycloheximide or actinomycin D. 相似文献
879.
Lactococcus lactis subsp. lactis strains isolated from various sprouted seed products were able to transfer the ability to ferment raffinose in conjugation experiments at frequencies between 10−4 and 10−7 per donor cell. There was no evidence of plasmid transfer, but pulsed-field gel electrophoresis analysis showed that all transconjugants had acquired large chromosomal insertions indicative of conjugative transposons. Raffinose transconjugants contained inserts of 45 or 60 kb at one of two chromosomal sites, and these inserts contained two copies of an element related to the lactococcal insertion sequence ISS1. 相似文献
880.
Most of the plant mitochondrial (mt) genomes that have been mapped are believed to be organized as master circle molecules
from which sub-genomic molecules arise through homologous recombination. We have evidence to suggest that a major part of
the rice mt genome is organized as independent, sub-genomic molecules or mt chromosomes, one of which has already been mapped.
This study is aimed at the identification of the other molecular entities that comprise the genome.
Pulsed-field gel electrophoresis of the native rice mt DNA and Southern analysis with different mt gene probes have shown
that in addition to the 117 kb mt chromosome, at least four more such molecules of sizes 130 kb, 95 kb, 70 kb and 56 kb account
for most of the rice mt genome. A majority of the rice mt genes that encode products involved in oxidative phosphorylation
are distributed among these five chromosomes. Partial restriction map of the 95 kborf 25/cox 3 chromosome, indicating the sites for the enzymesBglII andHindIII has also been determined. 相似文献