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1.
Photosystem II oxygen-evolving preparations with attached phycobilisomes were isolated from the thermophilic cyanobacterium Synechococcus sp. with beta-octylglucoside or digitonin. Fluorescence emission spectra of the two preparations determined at 77 K largely lacked a far red band which originates from photosystem I. The spectrum of the digitonin preparation was otherwise similar to that of intact cells, whereas the beta-octylglucoside preparation showed a pronounced band at 687 nm, which is considered to be emitted from phycobilisomes. The relative yield of phycobilin fluorescence was similar between the digitonin preparations and the cells but was considerably larger in the beta-octylglucoside preparations at room temperature. The quantum yield of ferricyanide photoreduction determined with light which is absorbed mainly by phycobiliproteins was 0.85 for the digitonin preparation and 0.57 for the beta-octylglucoside preparation. The results indicate that excitation energy is transferred from phycobilisomes to photosystem II reaction centers in the digitonin preparation as efficiently as in intact cells, while a significant portion of light energy harvested by phycobilisomes is not utilized by the primary photochemistry in the beta-octylglucoside preparation. Digitonin and beta-octylglucoside preparations had 65 and 48 chlorophyll a molecules per photosystem II reaction center, respectively. The beta-octylglucoside preparation contained twice as much phycocyanin and allophycocyanin per photosystem II reaction center as the digitonin preparation, which has a phycobiliprotein-to-photosystem II reaction center ratio very similar to that of cells. It is concluded that whereas the beta-octylglucoside preparation contains a considerable amount of free phycobilisomes, all phycobilisomes present in the digitonin preparation are physically and functionally linked to photosystem II reaction center complexes.  相似文献   

2.
3.
Previous studies (Hirao and Yanagimachi: Gamete Res. 1:3–12, 1978) have found that phospholipase C (PLC) preparations inhibit sperm-egg fusion. We have attempted to duplicate these results with PLC, as well as with a more specific enzyme, phosphatidyl-inositol-specific PLC. PLC preparations were applied externally to zona-free hamster eggs prior to incubation with sperm. Phosphatidylinositol-specific PLC did not inhibit sperm penetration. The degree of sperm-egg fusion observed after egg exposure to PLC, however, was dependent upon the purity of the commercial preparation. An impure sample of PLC inhibited sperm penetration, while a more purified preparation did not. The morphology of eggs was unaffected by exposure to phosphatidylinositol-specific PLC and the more purified PLC preparation. The impure preparation, however, was disruptive primarily to the egg plasma membrane as well as to internal organelle organization. The degree of damage by the impure PLC preparation was concentration dependent. The results suggest that as purity of the PLC preparation is increased, the adverse effects of PLC on sperm-egg fusion become negligible.  相似文献   

4.
The contribution of enzymes isolated from the microbial enzymic preparation to its total bacteriolytic activity was studied. The combined action of the lytic proteinase L2 and the lytic fraction L1 used in the same ratio as in the lysoamidase preparation resulted in a complete recovery of the bacteriolytic activity. During a 4-fold increase of the proportion of the lytic enzyme L1 as compared with lytic proteinase L2, the activity of the reconstituted preparation increased by 64%. Neutral phosphomonohydrolase, metal proteinase and the polysaccharide isolated from the lysoamidase preparation had no effect on the bacteriolytic activity of the reconstituted preparation. The polysaccharide isolated from lysoamidase increased the thermal stability of the preparation obtained up to that of lysoamidase.  相似文献   

5.
Fourteen laboratories participated in a collaborative study of a freeze-dried preparation of anti-infectious bursal disease virus serum to assess the suitability of the serum as a standard for use in the infectious bursal disease virus neutralization test. Ten laboratories carried out micro-virus neutralization tests and six carried out plaque reduction tests, two laboratories carrying out both tests. When titres were expressed as a proportion of that obtained for a reference preparation there was a marked reduction in variation between results from different laboratories. The use of a reference preparation was therefore of value when comparing results from different laboratories. It is proposed that the reference preparation used in this study be used as a standard to facilitate the comparison of results from different laboratories. The proposed standard contains by definition 10,000 UK units.  相似文献   

6.
Chalone-containing preparation has been obtained from ascitic Ehrlich's tumour by alcohol precipitation and the effect of various preparation doses on mitotic activity and DNA synthesis in the tumour has been studied. The preparation was shown to suppress tumour cell proliferation, acting on mitosis initiation and mitotic S phase as well as on DNA synthesis in the cells at S phase of mitotic cycle. The effect of the preparation on DNA synthesis in phase S cells was more pronounced than on cells entering DNA synthesis phase. The changes in all the parameters examined were dose-dependent. The preparation effect was tissue-specific.  相似文献   

7.
An improved and cost effective method to isolate FSH from buffalo pituitary glands is described here. The buFSH activity was monitored throughout by a highly sensitive heterologous radioimmunoassay (sensitivity 0.2 ng oFSH/mL) and the in vivo biological activity of the final preparation was also established. A biologically active buFSH-enriched preparation with a moderate recovery (42%) was obtained. The yield of the final buFSH-enriched preparation was 26.5 mg/kg of buffalo pituitary gland. In SDS-PAGE, the purified buFSH resolved as a heterodimer of 30 kDa molecular size, with a 21 kDa presumptive alpha-subunit. This preparation was also characterized in terms of biological and some of its physicochemical properties. A high-titer antiserum to buFSH was also raised in rabbit using this preparation. The reagents generated, buFSH and buFSH-specific polyclonal antisera, have possible diagnostic and therapeutic usage for improvement of reproductive health of water buffaloes.  相似文献   

8.
A preparation of somatropin (recombinant DNA-derived human growth hormone) was prepared as lyophilised ampoules according to WHO procedures for international biological standards. The candidate preparation (98/574) was evaluated in an international collaborative study (16 laboratories, nine countries), with the following aims: (i) to determine the suitability of the preparation to serve as the International Standard for somatropin by studying its performance in the current range of physico-chemical and biological assay methods employed for somatropin; (ii) to assign a content in terms of the existing (first) International Standard for somatropin, using the currently recognised assay procedure (Size Exclusion High Performance Liquid Chromatography, SE HPLC); (iii) to confirm the specific biological activity of the candidate preparation; (iv) to confirm the stability of the candidate preparation. On the basis of the collaborative study WHO agreed that: the preparation in ampoules coded 98/574 is suitable to serve as the next WHO International Standard for somatropin; the preparation in ampoules coded 98/574 should be established as the second International Standard for somatropin, with a defined ampoule content of 1.95 mg total somatropin plus somatropin-related proteins per ampoule; the specific activity of the preparation should be defined as 3.0 IU/mg somatropin.  相似文献   

9.
Sodium ascorbate caused an increased lipid peroxidation and a large decrement in [3H]spiroperidol binding in a rat neostriatal membrane preparation (preparation C). Both effects were greater at intermediate (0.05 and 0.5 mM) than at higher or lower ascorbate concentrations. In contrast, in another neostriatal membrane preparation (preparation A), there was no loss of [3H]spiroperidol binding and only a small increase in lipid peroxidation caused by ascorbate. However, both the ascorbate-induced increase in lipid peroxidation and loss of [3H]spiroperidol binding were greatly enhanced in preparation A by the addition of iron salts. In experiments designed to explore reasons for these apparent discrepancies, we discovered that the method of tissue preparation was a critical factor. The ascorbate effects were consistently greater in a tissue preparation which was originally homogenized in an isotonic sucrose medium and centrifuged, and the cell debris discarded (as was done in preparation C), than in one in which the tissue was homogenized in a hypotonic medium and in which no low-speed centrifugation was done (as was done in preparation A). In other experiments, of several cations tested, only ferrous and ferric potentiated the above-described effects of ascorbate. Some ascorbic acid derivatives (e.g., isoascorbic acid) had properties similar to those of ascorbic acid, whereas several reducing agents could, in the presence of added iron salts, cause both a lipid peroxidation and a loss of [3H]spiroperidol binding.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

10.
The results of the trial of an immunostimulating preparation, consisting of Klebsiella pneumoniae, Proteus, Escherichia coli and Staphylococcus antigenic complexes, on 20 patients with acute pulmonary abscess and bronchiectasis are presented. The preparation was introduced subcutaneously in 5 injections. The preparation was found to have low reactogenicity, and in the course of immunotherapy the manifestations of systemic and local reactions became considerably less pronounced. Immunotherapy produced a good curative effect, objectively manifested by a decrease in coughing and in the amount of sputum gradually changing its character. After the fourth and fifth injections the patients no longer ejected purulent sputum. Fluoroscopic examination revealed a considerable decrease in the size of the pathological focus. The preparation stimulated immunological reactions, and immunization resulted in a considerable increase in the titer of antibodies to all components of the combined preparation, as well as in an increase in the number of functionally active T-lymphocytes, in the blood of the patients.  相似文献   

11.
Bromelain is a basic, 23.8 kDa thiol proteinase obtained from the stem of the pineapple plant (Ananas comosus) and is unique for it contains a single histidine residue (His-158) in the polypeptide. Based on the technology of protein separation with immobilized metal ion affinity chromatography (IMAC), a method for oriented immobilization of bromelain was selected. Bromelain was successfully immobilized on iminodiacetic acid carrier Sepharose 6B. Cu2+ complexed with iminodiacetate (IDA) was used as the chelating ligand to bind the lone histidine on bromelain. Simultaneously, preparation of a high affinity immobilized preparation was attempted using a soluble cross-linked preparation of bromelain on Cu-IDA-Sepharose. However this second method proved unsuccessful, possibly due to poor histidine accessibility in the cross-linked preparation. The immobilized preparation obtained using uncrosslinked bromelain was more resistant to thermal inactivation, as evidenced by retention of over enzyme 50% activity after incubation at 60 °C, as compared to 20% retained by the native enzyme. The immobilized preparation also exhibited a broader pH-activity profile in acidic range. The native, immobilized and soluble cross-linked bromelain showed apparent Michaelis constant (Km) values of 1.08, 0.42, 1.56 mg/ml, respectively, using casein as the substrate. While the maximum velocity (Vmax) values of the soluble and immobilized preparations were comparable, cross-linked preparation showed a 20% decrease, suggesting inactivation. The mild conditions used for predominantly oriented immobilization exploiting the unique property of single histidine, the high recovery of immobilized preparations, the stability, reusability and the regenerability of the matrix are the main features of the method reported here.  相似文献   

12.
A soluble enzyme preparation, which catalyses the polymerization of mannose, was obtained by Triton X-100 extraction of a particulate fraction derived from Phaseolus aureus hypocotyls. The product that resulted when GDP-alpha-d-mannose was used as a substrate was a beta-(1-->4)-linked mannan, about three-quarters of which was alkali-insoluble. The mannose-polymerizing enzyme activity was at least as great in the soluble preparation as in the particulate preparation, and the specific activity of the solubilized enzyme was greater by a factor of at least 3.5. Kinetic studies of the soluble enzyme indicate that the apparent K(m) is 55-62mum, and a disproportionate increase in rate is observed at high concentrations. GDP-alpha-d-glucose is a strong competitive inhibitor of the mannose-polymerizing reaction, with an apparent K(i) of 6.2mum. The soluble enzyme is relatively unstable, losing about two-thirds of its original activity in 5h at 0 degrees C or in 24h at -20 degrees C. A solvent (acetone, butanol, diethyl ether)-extracted particulate preparation, which also exhibits the same enzyme activity, is more stable, retaining full activity for at least 5 days at -20 degrees C. There was no polymerizing-enzyme activity in the soluble enzyme preparation when UDP-d-glucose, UDP-d-galactose, UDP-d-xylose, UDP-l-arabinose or UDP-d-glucuronic acid were used as substrates. However, the soluble enzyme preparation would catalyse the polymerization of glucose, with GDP-d-glucose as substrate.  相似文献   

13.
为研究酶制剂对烤烟上部叶品质提升的影响,以中烟100为材料,采用烘烤前叶面喷施酶制剂的方法,分析了不同酶制剂对烤烟上部叶化学成分、游离态和糖苷结合态中性香气成分的影响。结果表明:不同酶制剂能不同程度的降低烤烟的蛋白质含量,改善烟叶化学成分,提高游离态和糖苷结合态中性香气成分的含量;喷施酶制剂对烟叶蛋白质、总糖、还原糖、总氮均有显著的影响,而对烤烟钾、氯的影响则未达到显著水平;混和喷施酶制剂相对于单独喷施酶制剂对烟叶品质的影响更显著。  相似文献   

14.
The effects of different inactivating agents on the biological activity of the histamine sensitization factor of Bordetella pertussis toxin were examined. The agents were used for inactivation in the preparation of whole cell pertussis suspension. The histamine sensitizing activity was reduced to 36.9-13.3% by treatment with glutaraldehyde, to about 50% by treatment with formaldehyde and by the acetone-II treatment, relative to the reduction by heat treatment. Treatment with thimerosal and the acetone-I treatment did not reduce the histamine sensitizing activity as the 50% histamine sensitizing doses of the heat inactivated pertussis preparation, the thimerosal inactivated pertussis preparation and the acetone-I treated pertussis preparation were very similar. Glutaraldehyde has thus been found to be a better inactivating agent for the preparation of a safe pertussis suspension as it considerably reduced the histamine sensitizing activity of pertussis toxin.  相似文献   

15.
This paper reports a comprehensive study of the biological stability of an immunoaffinity purified preparation of human thyroid stimulating hormone (TSH) and provides a reference against which future natural or synthetic preparations may be compared. The stability of the hormone preparation was investigated using the accelerated degradation method. The bioassay of the TSH was carried out in mice using a modified McKenzie method. Analysis of the results showed that the preparation was as stable as other TSH preparations purified by conventional methods.  相似文献   

16.
The molecular composition of the volutin granule of yeast.   总被引:5,自引:3,他引:2       下载免费PDF全文
The effects of insulin on glucose uptake and lactate release in the perfused working rat heart have been investigated in three types of preparation: (i) a control low-workload preparation; (ii) an increased-pressure-workload preparation, simulating conditions of aortic pressure encountered in vivo; (iii) an increased-volume-workload preparation, where pumping work done is approximately the same as (ii) but coronary flow is restricted because of the decreased aortic pressure. Insulin stimulated glucose uptake and lactate release in preparations (i) and (ii), but failed to do so in preparation (iii). It was considered possible that preparation (iii) was hypoxic, thus necessitating a maximal stimulation of glucose uptake. This was confirmed by improving cardiac oxygenation by addition of stroma-free haemoglobin to the perfusate in preparation (iii). Under these conditions in the absence of insulin, glucose uptake and lactate release were decreased compared with perfusions in the absence of haemoglobin. Insulin stimulation of both processes was restored. We conclude that the failure of other workers to observe insulin effects on glucose uptake and lactate release under physiological workloads [preparation (ii)] may be a consequence of intracellular hypoxia in their preparations.  相似文献   

17.
We studied the fungicidal activity of a biological preparation from the fungi of the genus Chaetomium against soil phytopathogenic fungi Rhizoctonia solani and Fusarium oxysporum. The inhibitory effect of the preparation under study depended on its concentration, duration of storage, and growth characteristics of pure cultures of the phytopathogens. The highest (98.8%) inhibitory activity was observed on day 3 of the interaction with Rhizoctonia solani. After a 2-year storage, this preparation was capable of inhibiting the growth of the phytopathogens only at high doses. The preparation precluded the development of bare patch and increased the productivity of potato plants. The preparation may serve as an alternative to chemical fungicides for plant protection.  相似文献   

18.
Catalase was isolated in a pure form from sweet potato rootmicrobodies by simple procedures including ammonium sulfatefractionation and Sepharose 6B column chromatography. A singleprotein band was detected after polyacrylamide gel electrophoresisof the purified preparation. The catalase consisted of polypeptideswith a molecular weight of 60,000 when analyzed by sodium dodecylsulfate-polyacrylamidegel electrophoresis, while the molecular weight of the enzymewas about 240,000 when estimated from sucrose density gradientcentrifugation. The enzyme's ratio of absorbance at 280 nm tothat at 405 nm was about twice that of mammalian catalase. Thecatalase showed a maximal activity at pH 6.5–8.5 but wasstable only at alkaline pHs. In double immunodiffusion tests,antiserum against the purified preparation formed a single precipitinline with the crude soluble fraction from sweet potato roottissue as well as with the purified preparation. The antiserumhad no ability to inhibit the activity, but catalase in boththe crude fraction and the purified preparation was completelyprecipitated by the antiserum. (Received August 20, 1981; Accepted January 5, 1982)  相似文献   

19.
Bovine serum albumin (BSA) preparations are commonly employed as "carrier" or "protective" proteins in the solutions used to dissolve gonadotropin preparations. The present report describes a BSA preparation that was found to contain a factor that inactivated follicle-stimulating hormone (FSH). Four different BSA preparations (designated BSA1, BSA2a, BSA2b, BSA3) were studied. The FSH preparation (NIH-FSH-S16) was dissolved in 0.15 M NaCl, containing the various BSA preparations. The FSH solutions were injected subcutaneously, twice daily, for 5 days into hypophysectomized immature female rats bearing estrogen capsules. Twenty-four hours after the last injection, the rats were decapitated, and the ovaries were removed, trimmed and weighed. The FSH preparation produced ovarian weight gain when BSA1, BSA2b, or BSA3 was used, but not when BSA2a was used in the vehicle. In animals injected with the FSH dissolved in BSA1 vehicle and injected at a separate site with BSA2a solution, the FSH preparation was fully active, which indicates that contact of the BSA2a preparation with FSH was required for the inactivating factor to be operant. Indeed, after incubation in BSA2a solution, the radiolabeled FSH preparation exhibited a slight decrease in apparent molecular size when chromatographed on a Sephadex G-100 column. This result suggests that the BSA2a preparation contained a factor that may have inhibited FSH by degrading it.  相似文献   

20.
Antibody formation in vitro was studied using erythrocytes (RBC) as antigen and immunocytoadhesion as the technique for detection of antibody-forming cells. Spleen cells (SPC) of nonimmune mice gained the ability to produce antibody after treatment with ribonucleic acid (RNA) preparation extracted from allogeneic mice immunized with xenogeneic or allogeneic RBC. It was also found that a small proportion of SPC from individual mice of certain strains formed antibody against autologous RBC when the cells were treated in vitro with RNA preparation obtained from the spleen of an allogeneic mouse immunized with RBC of that individual. No converting ability was observed in the RNA preparation from spleen of nonimmune autologous or allogeneic mice. The converting activity of immune RNA preparation was shown to be sensitive to ribonuclease treatment. These evidences exclude the possible contribution of antigen or fragments thereof in the RNA preparation to the induction of antibody formation in RNA recipient cells.  相似文献   

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