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1.
Molecular and Cellular Biochemistry - 相似文献
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Simultaneous saccharification and protein enrichment fermentation of sugar beet pulp 总被引:1,自引:0,他引:1
Summary A product with 40 % protein content was obtained from sugar beet pulp (1.25–2.0 mm) in 48 h one stage (simultaneous) saccharification/fermentation process under optimized conditions using a specific enzyme mixture andCandida
tropicalis strain, also saving about 40 % enzymes in comparison to a 2-stage process. 相似文献
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From the hot petrol extract of Piper cubeba ftuits, six lignans were isolated. Two of these, which have been obtained from a natural source for the first time, have been characterized as (2R,3R)-2-(3″,4″,5″-trimethoxybenzyl)-3-(3′,4′-methylenedioxybenzyl)-1,4-butanediol [(?)-dihydroclusin] and (3R,4R)-3,4-bis-(3,4,5-trimethoxybenzyl)tetra-hydro-2-furanol [(?)-cubebinin]. (?)Cubebin, (?)-hinokinin, (?)-clusin and (?)-dihydrocubebin were also found in this plant. Only (?)-cubebin has been reported so far from this source. 相似文献
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Immunoaffinity purified Sm/RNP antigens from buffalo and goat liver were studied to determine the role of RNA and proteins
towards the antigenicity of Sm and RNP antigens. A more direct approach using enzyme-linked immunosorbent assay on nylon beads
has been utilized to look into the problem. The effect of enzyme treatment and the role of RNA and protein fractions in influencing
antigenicity have been described. RNA seems to be involved in the maintenance of RNP specific polypeptides in suitable conformation
so as to keep them in solution. Removal of RNA leads to insolubilization of RNP specific polypeptides. Antibodies to Sm and
RNP antigens have been shown to cross react with poly A containing heterogeneous nuclear ribonucleoprotein with no cross reactivity
with thymus RNA or DNA. 相似文献
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The heterogeneous vegetation mosaic of the South Turkana region of north Kenya is associated with diversity in the region's physical environment. The abundance and distribution of the dominant species are related to gradients in those abiotic factors that influence water availability, including precipitation, soil texture, and topographic relief. Research focused on three Acacia species that are a major component of the Turkana vegetation; A. tortilis, A. senegal, and A. reficiens. These species each exhibit a different response to variations in abiotic factors. Consequently, species abundance varies independently across the landscape, creating a continuum of intergrading populations. Community types can be identified within the mosaic of intergrading populations. Although community borders are not discrete due to continual change in species abundance, types are identifiable and are repeated in areas with similar environmental conditions. The landscape patterns are representative of Whittaker's (1953) climaxas-pattern, with communities created by individual patterns of populations responding to environmental gradients, creating a continuum of community change across the landscape. 相似文献
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The DNP derivative of sonicate antigens of the H37Ra strain ofMycobacterium tuberculosis (Ra-DNP) is known to induce marked B-cell proliferation. In order to understand whether B-cell proliferation in response
to Ra-DNP was antigen driven or represented a non-specific mitogenic effect of Ra-DNP, the effect of Ra-DNP was compared with
that of lipopolysaccharide a potent B-cell mitogen. Parameters used for comparison were (i) thymidine incorporation, (ii)
viable cell counts, (iii) amount of lg secreted, (iv) isotype profile of Ig released and (v) cell cycling pattern of B-cells
in culture. Overall the effect of Ra-DNP was found to be essentially similar to that of lipopolysaccharide for all parameters
examined. Yet quantitatively, the effect of the former was always relatively poorer. At optimal doses, the effect of Ra-DNP
ranged from 50 to 70% of the lipopolysaccharide effect in different assays. These results suggest that Ra-DNP may have a B-cell
mitogenic effect similar to the effect of lipopolysaccharide, but all B-cells may not respond to Ra-DNP. 相似文献
8.
Ashok K. Srivastava Rafick-Pierre Sékaly Jean-Louis Chiasson 《Molecular and cellular biochemistry》1993,121(2):127-133
The effect of nicotinamide-adenine dinucleotides (NAD+ and NADP+) on Ca2+ transport in rat liver nuclei was investigated. Ca2+ uptake and release were determined with a Ca2+ electrode. Ca2+ uptake was dependent on adenosine triphosphate (ATP; 2mM). The presence of NAD+ (2mM) or NADP+ (1 and 2mM) caused a significant inhibition of Ca2+ uptake following addition of 2mM ATP. Ca2+, which accumulated in the nuclei during 6 min after ATP addition, was significantly released by the addition of NAD+ (0.5–2mM) or NADP+ (0.1–2mM). However, the effect of NADH (2mM) or NADPH (2mM) on Ca2+ uptake and release clearly weakened in comparison with the effects of NAD+ and NADP+. Meanwhile, ryanodine (10M), thapsigargin (10M) or oxalate (0.5mM) had no effect on Ca2+ uptake and release in rat liver nuclei. These reagents did not significantly alter the effects of 2mM NAD+ on Ca2+ uptake and release. Thus, NAD+ and NADP+ had a potent effect on Ca2+ transport in rat liver nuclei. The present findings suggest that the liver cytosolic NAD+ (NADP+) is a factor in the regulation of the nuclear Ca2+ concentration. (Mol Cell Biochem121: 127–133, 1993) 相似文献
9.
Summary Precipitation of proteins has been achieved following passage of direct electric current in various protein solutions. Application of as low as 3 V of electric current showed precipitation but the rate increased with increase in electric current. With 9 V there was more than 85% precipitation of protein within 15 min. Precipitation occurred at a wide range of pH and temperature. Electrophoretic analysis of precipitated proteins show that they are not denatured by application of electric current. Proteins thus precipitated can be easily recovered by centrifugation. 相似文献
10.
The ectendomycorrhizal fungiWilcoxina mikolae isolates CSY-14 and RMD-947 andW. rehmii isolate CSY-85 were grown in pure culture under iron-limiting conditions. All three isolates tested positive for siderophore formation using both the ferric perchlorate assay and a sensitive HPLC iron-binding assay. A peptide siderophore was isolated from the culture medium by HPLC and shown to contain the amino acids serine, glycine and ornithine in a 1:2:3 ratio. This siderophore was identified as ferricrocin on the basis of electrospray mass spectroscopy and its co-chromatography in two different HPLC systems with ferricrocin isolated fromAspergillus fumigatus. Ferricrocin was the only siderophore isolated from theseWilcoxina cultures. This is the first report of siderophore formation by ectendomycorrhizal fungi. 相似文献