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1.
Summary A mutant strain of Rhodococcus equi accumulates three metabolites from the androst-4-ene-3,17-dione or from its degradation intermediate, 3a-H-4(3'-propionic acid)-7a-methylhexahydro-1,5-indanedione (MEPHIP). These three metabolites are: 3a-H-4a(3'-propionic acid)-5-hydroxy-7a-methylhexahydro-1-indanone--lactone (HIL); 3a-H-4(3'-trans acrylic acid)-5-hydroxy-7a-methylhexahydro-1-indanone (2'-5-hydroxy-MEPHIP); and 3a-H-4(3'-hydroxy-3'-propionic acid)-5-hydroxy-7a-methylhexahydro-1-indanone (3'-hydroxy-HIL). The behaviour of this mutant allows us to propose a pathway for degradation of the intermediates, methylperhydroindanone propionates. However, during this degradation, the side-chain propionate was eliminated by a-oxidation mechanism. Offprint requests to: A. Miclo  相似文献   

2.
Summary A quantitative histochemical analysis of almost 200 mouse triceps surae muscle fibres is presented, together with some data from similar surveys of rabbit skeletal muscles. In the main work, ten parameters are considered: mean diameter, and reaction intensities (estimated as apparent absorbances) of three markers for oxidative-lipolytic metabolism, three for metabolism associated with glycolysis and three for the type of myosin. Cytoarchitecture of one deposit (succinate dehydrogenase) is also noted.Frequency histograms for each parameter and correlation analyses for all possible pairings demonstrate that markers within the same metabolic system are not truly equivalent. Therefore, fibre typing in terms of just one marker from each system cannot be independent of the markers used. Selecting the most sharply discriminatory pair-myosin ATPase (following formalin and alkaline pretreatment) and glycogen phosphorylasea — one isolates four more-or-less discrete clusters of points. Taking succinate dehydrogenase also into account, to indicate characteristic oxidative levels within clusters, one can label the indicated fibre types (following a well-established muscle terminology) as fast, essentially glycolytic (FG), fast, oxidative and glycolytic (FOG), fast, essentially-oxidative (FO) and slow, essentially oxidative (SO). However, with either -glycerophosphate dehydrogenase or the periodic acid-Schiff reaction (PAS) as glycolytic marker, the FO-group is not separated from the FOG; and with oxidative level as a primary clustering criterion FG and FOG groups are continuous. An entirely different basis for classification-cytoarchitecture-also suggests four fibre types but the divisions most comparable to the FG/FOG and FOG/FO boundaries are best located somewhat differently again.Some of the techniques of formal cluster analysis are next introduced. These are ways of searching for similarities (defined in terms of various objective criteria) in large volumes of essentially multivariate data.Within a sample, considered representative of acceptably artefact-free fibres, virtually the same four groups as before are identified. The only difference is that what were earlier grouped as the most oxidative FG fibres are now classed FOG; the acid-pretreated myosin ATPase reaction (previously little considered) contributes to this reclassification. At the five cluster level, a strong tendency exists for this small group, designated FG(O), to appear separately. At the two-cluster level classical distinctions in terms of high/low oxidative capacity, glycolytic capacity and myosin ATPase activity are each favoured by different similarity criteria.Surveying the whole sample of fibres, only criteria which favour non-rambling clusters produce similar results to those above. However, an artefact in one reaction, for which there is strong internal evidence, is able to explain almost all other effects. These results do not prove the biological rightness of a 4–5 cluster pattern, but they do demonstrate its mathematical strength and the reactions upon which it depends.The suggestion is made that cluster analysis and related multivariate statistical methods could profitably be applied to a wide range of further problems in cell taxonomy.  相似文献   

3.
Incubation of synthetic Man\1-4GlcNAc-OMe, GalNAc1-4GlcNAc-OMe, Glc1-4GlcNAc-OMe, and GlcNAc1-4GlcNac-OMe with CMP-Neu5Ac and rat liver Gal1-4GlcNAc (2-6)-sialyltransferase resulted in the formation of Neu5Ac2-6Man1-4GlcNAc-OMe, Neu5Ac2-6GalNAc1-4GlcNAc-OMe, Neu5Ac2-6Glc1-4GlcNAc-OMe and Neu5Ac2-6GlcNAc1-4GlcNAc-OMe, respectively. Under conditions which led to quantitative conversion of Gal1-4GlcNAc-OEt into Neu5Ac2-6Gal1-4GlcNAc-OEt, the aforementioned products were obtained in yields of 4%, 48%, 16% and 8%, respectively. HPLC on Partisil 10 SAX was used to isolate the various sialyltrisaccharides, and identification was carried out using 1- and 2-dimensional 500-MHz1H-NMR spectroscopy.Abbreviations 2D 2-dimensional - CMP cytidine 5-monophosphate - CMP-Neu5Ac cytidine 5-monophospho--N-acetylneuraminic acid - COSY correlation spectroscopy - DQF double quantum filtered - HOHAHA homonuclear Hartmann-Hahn - MLEV composite pulse devised by M. Levitt - Neu5Ac N-acetylneuraminic acid - Neu5Ac2en 2-deoxy-2,3-didehydro-N-acetylneuraminic acid  相似文献   

4.
The insulin-producing pancreatic islet -cell, characterized by low proliferative potential, is normally not responsive to the polypeptide epidermal growth factor (EGF) or its homolog transforming growth factor (TGF-). Since EGF receptors in other tissues can be up-regulated by other growth factors and by cytokines, we have in this paper investigated whether such a -cell responsiveness to TGF-, or EGF, can be conferred by co-culture with interferon (IFN-), tumor necrosis factor (TNF-) or transforming growth factor (TGF-) in various combinations. To this end, fetal rat pancreatic islets enriched in -cells were isolated and cultured for 3 days with or without 200 pM or 20 nM TGF-. It was found that neither of these TGF- concentrations affected -cell mitogenesis, insulin content or insulin secretion. However, IFN- (1000 U/ml) evoked a modest stimulation of -cell replication, while suppressing insulin secretion and leaving the islet insulin content unaltered. TNF- (1000 U/ml), on the other hand, affected none of these parameters either alone or in any combination with TGF- or IFN-. However, when TNF- or IFN-, either alone or in combination, were combined with the cytokine interleukin-1, this resulted in islet disintegration, whereas the latter cytokine alone did not exert any gross necrotic changes evident by light microscopy. TGF- (500 pM) stimulated insulin secretion but did not influence islet insulin content or -cell mitogenesis either alone or in combination with TGF- (200 pM or 20 nM). In no instance could any mitogenic or secretory response to low or high concentrations of TGF- be conferred by IFN-, TNF- or TGF- whether used alone or in combinations. Hence, responsiveness to TGF- or EGF in the -cell obviously cannot be achieved by any of these peptides.Abbreviations EGF epidermal growth factor - IFN- interferon - TGF- transforming growth factor - TGF- transforming growth factor - TNF- tumor necrosis factor   相似文献   

5.
Résumé Nous avons fait élever des larves d'Anergates atratulus par des ouvrières deMyrmica laevinodis à 22°C. Pour y parvenir, il n'est pas utile de faire hivernerensemble les larves d'Anergates et les ouvrières deMyrmica. La présence de larves autochtones n'empêche pas lesMyrmica d'élever des larves d'Anergates. Dans toutes les expériences lesMyrmica ont été soumises au fridavant de recevoir des larves d'Anergates. Aucune reine deMyrmica n'a été utilisée dans ces expériences.Sur les 64 larves d'Anergates que nous avons utilisées, 38 se sont transformées en imagos. C'est au début de l'adoption et au moment des métamorphoses que périrent la plupart des 26Anergates perdus. Les femelles vécurent en général 2 ou 3 jours et cherchèrent très tôt à quitter le nid natal. Les mâles vécurent 2 à 3 semaines.
Summary Larvae ofAnergates atratulus were experimentally reared by workers ofMyrmica laevinodis, at 22°C. An overwintering of both larvae ofAnergates and workers ofMyrmica is not necessary for the success of that experiment. The presence of larvae ofMyrmica does not keep theMyrmica from rearing larvae ofAnergates. The workers ofMyrmica have been cooled, in all the experiments, before receiving larvae ofAnergates. No queen ofMyrmica have been used in that experiments.38 of the 64 larvae ofAnergates used became imagos. Most of the 26 lostAnergates died at the beginning of the adoption and during the metamorphosis. The females lived generally 2 or 3 days and tried, very early, to leave their native nest. The males lived 2 or 3 weeks.

Anergates atratulus Myrmica laevinodis, 22 . bmecme Anergates Myrmica. Myrmica Anergates. Myrmica Anergates. Myrmica . 64 Anergates , 38 . 26 Anergates 2 3 . 2 3 .
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6.
The solvent effects of cyclopentyl methyl ether (CPME) on the reaction rates and enzyme enantioselectivity in the enantioselective transesterifications of racemic 6-methyl-5-hepten-2-ol (racemic sulcatol: SUL) and racemic 2,2-dimethyl-1,3-dioxolane-4-methanol (racemic solketal: SOL) with a series of enol esters catalyzed by Pseudomonas cepacia lipase co-lyophilized with cyclodextrins (-, -, -, partially methylated -,and 2,3,6-tri-O-methyl--cyclodextrin: CyD; CyD; CyD; Me1.78 CyD; Me3CyD) were investigated and compared with those in diisopropyl ether (IPE). In the case of SUL, enzyme activities of the co-lyophilizate with Me1.78 CyD in CPME were lower than those in IPE with every acyl source, however, the absolute enantiopreference was shown in the transesterification with vinyl butyrate (VBR) in IPME. When the substrates were SOL and VBR, the enzyme activities in CPME were greatly enhanced as high as 1.6–9.8-fold, while the enantioselectivities in CPME were comparable to those in IPE.Revisions requested 16 December 2004; Revisions received 17 January 2005  相似文献   

7.
Oxidative injury and antioxidant responses were investigated in two banana genotypes (Musa AAA Berangan and Musa AA Mas) subjected to 40 % PEG-induced water stress. PEG treatment resulted in oxidative injury, as expressed in increased lipid peroxidation and reduced membrane stability index, in both cultivars; however, greater oxidative injury was detected in Mas. Under PEG treatment, catalase activity and glutathione reductase activity were enhanced in both cultivars, but were higher in Mas. Ascorbate peroxidase activity was enhanced in Berangan under water stress, but was unaffected in Mas. Meanwhile, superoxide dismutase activity was inhibited in both cultivars under water stress, but higher activity was detected in Berangan. Higher ascorbate peroxidase and superoxide dismutase activities were associated with greater protection against water stress-induced oxidative injury.  相似文献   

8.
A brief history of the discovery of photosynthetic phosphorylation by chloroplasts and bacterial chromatophores is presented. Arnon early introduced the terminology of Cyclic and Non-cyclic photophosphorylation and Cyclic and Non-Cyclic electron transport to the processes observed in illuminated chloroplasts. He made major contributions to the elucidation of these processes and stressed their great biological significance. Investigations of the electron transport components of chromatophores have led to the isolation, purification and crystallization of bacterial reaction centers. The development of three-dimensional molecular structures, and the characterization of their electron transfer components have provided a great deal of information about the early reactions of bacterial photosynthesis. The electron transfer schemes presented clearly support the cyclic nature of light-induced electron transfer. Recent developments in the understanding of ATP synthesis in oxidative phosphorylation by mitochondria and in photophosphorylation by chloroplasts and bacterial chromatophores are discussed.Abbreviations ADP, ATP adenosine 5-di- and triphosphates - NADP+, NADPH oxidized and reduced Nicotinamide-adenine dinucleotide phosphate - RC reaction center - EPR electron paramagnetic resonance - F0F1 ATP-synthase (synthetase) of mitochondria, chloroplasts, and of chromatophores - F0 membrane portion of ATP-synthase - F1-ATPase water soluble sector of ATP-synthase  相似文献   

9.
The influence of some macronutrients, especially NH4NO3 and KNO3, on root development of microcuttings from 3 apple scion cultivars is discussed. A reduction of the level of NH4NO3 in the medium from full strength to 1/4 strength significantly increased the percentage rooting of Gala and Royal Gala, but not Jonagold. Further reduction of NH4NO3 level from 1/4 strength to zero significantly reduced the percentage of rooting in Gala but not Royal Gala. Jonagold rooted best at zero concentration NH4NO3. Without NH4NO3, rooting percentages were as high as 100% for all 3 cultivars when KNO3 was provided at full strength. The results show that adventitious roots can be induced on apple scion cultivars by media manipulation.  相似文献   

10.
EF-1a binds aminoacyl-tRNA to the ribosome with the hydrolysis of GTP; the complex facilitates the exchange of GDP for GTP to initiate another round of elongation. To examine the subunit structure of EF-1 and phosphorylation by protein kinase CKII, recombinant , , and subunits from rabbit were expressed in E. coli and the subunits were reconstituted into partial and complete complexes and analyzed by gel filtration. To determine the availability of the and subunits for phosphorylation by CKII, the subunits and the reconstituted complexes were examined as substrates for CKII. Formation of the nucleotide exchange complex increased the rate of phosphorylation of the subunit and reduced the Km, while addition of to or the complex inhibited phosphorylation by CKII. However, a had little effect on phosphorylation of . Thus, the and subunits in EF-1 were differentially phosphorylated by CKII, in that phosphorylation of was altered by association with other subunits, while the site on was always available for phosphorylation by CKII. From the availability of the subunits for phosphorylation by CKII and the composition of the reconstituted partial and complete complexes, a model for the subunit structure of EF-1 consisting of (22)2 is proposed and discussed.  相似文献   

11.
Summary Thirty-one toria genotypes were compared with three well-established cultivars, Ludhiana Composite-2, K-1 and TCSU-2 (standard testers). The genotypes, which were almost identical to a standard tester in response to environmental variations and which also had other desirable characteristics, were considered to be acceptable for commercial cultivation. Using this criterion, TCSU-7, TH-5 and TH-4 were found to be acceptable for commercial cultivation. TH-4 and TCSU-7 were found superior to TH-5 if r2 can be considered as a measure of the agronomical manipulations expected in environmental variations.  相似文献   

12.
Three sialosylated and three neutral glycosphingolipids sharing a common iso-neolacto core were isolated from porcine kidney cortex. They were purified by preparative HPTLC, and were characterized by partial exoglycosidase hydrolysis followed by thin layer chromatography and immunostaining with anti-Gal13Gal, anti-type 2 lactosamine and anti-Lewisx antibodies, methylation analysis, MALDI-TOF mass spectrometry and 1H-NMR spectroscopy. Among neutral glycolipids, one was a known structure, VI3VI3(Gal)2-iso-nLc8Cer, and two were novel structures differing by the number of Gal3Lewisx determinants: VI3VI3(Gal)2V3Fuc-iso-nLc8, and VI3VI3(Gal)2 V3V3(Fuc)2-iso-nLc8. The single Gal3Lewis x determinant was found on the 6-linked antenna. Among sialosylated glycolipids, two had been previously found in other species and tissues, VI3VI3(NeuAc)2-iso-nLc8, and VI3NeuAcVI3Gal-iso-nLc8. A novel structure was discovered presenting a Gal3Lewisx determinant on the 6-linked antenna and a N-acetylneuraminic acid on the 3-linked antenna, VI3NeuAcVI3GalV3Fuc-iso-nLc8. These results indicate that, in vivo, the porcine kidney 3fucosyltransferase synthesizes the Gal3Lewisx determinant, acting on the 6-linked before the 3-linked Gal3neolactosamine, and appears unable to synthesize the sialosylated Lewisx determinant on neolactoseries glycolipids.  相似文献   

13.
Summary Human liver alcohol dehydrogenase (ADH) variants were screened in random autopsy specimens from 53 North German and 34 Japanese individuals. Based on pH-activity profile and electrophoretic pattern, only ADH2 and ADH3 variants were detected. In relatively fresh specimens, an anodic band or -ADH band was also observed. The recently reported new molecular forms collectively called ADHIndianapolis (Bosron et al. 1980) could not be demonstrated and therefore may be confined hitherto only to the American black population.This paper is dedicated to Professor Dr. Dr. H. Baitsch on his 60th birthday  相似文献   

14.
A new method for cytofluorometric analysis of mitochondrial membrane potential has been developed by using TMRM as a cationic, mitochondrial selective probe. The method is based on limited treatment of cultured cells with digitonin which permeabilises the plasma membrane and leaves mitochondria intact. The resulting signal of TMRM-stained cells thus represents only the probe accumulated in mitochondria. Fibroblasts and cybrids were used as a model cell systems and optimal conditions for digitonin treatment and staining by TMRM were described. The TMRM signal collapsed by valinomycin, KCN and antimycin A and FCCP titration was used to gradually lower and characterise the stability of . The method is suitable for sensitive measurement of in different types of cultured cells.  相似文献   

15.
Summary the organization of the -globin genes was studied by restriction endonuclease mapping, in subjects carrying the variant Hb J Mexico. A subject homozygous for Hb J synthesized both Hb J (about 55%) and Hb A and had two loci per chromosome. His restriction site map was found to be identical to that obtained with a normal DNA, except for a mutant Bgl II site which was observed on the Hb J chromosome proximal to the 5-locus. We have also mapped the DNA of a compound heterozygote for Hb J and -thalassemia, who synthesizes 38% Hb J and we have found a single gene corresponding to a –3.7 haplotype on one chromosome and two genes, respectively J and A, on the other.  相似文献   

16.
The tetrasaccharides GalNAcß1-4[NeuAc2-3]Galß1-4Glc and GalNAcß1-4[NeuAc2-3]Galß1-4GlcNAc were synthesised by enzymic transfer of GalNAc from UDP-GalNAc to 3-sialyllactose (NeuAc2-3Galß1-4Glc) and 3-sialyl-N-acetyllactosamine (NeuAc2-3Galß1-4GlcNAc). The structures of the products were established by methylation and1H-500 MHz NMR spectroscopy. In Sda serological tests the product formed with 3-sialyl-N-acetyllactosamine was highly active whereas that formed with 3-sialyllactose had only weak activity.  相似文献   

17.
    
Summary As has been shown previously, RNA polymerase subunit ts-mutation rpoC1 results in an overproduction of RNA polymerase subunits at nonpermissive temperature. The mutant enzyme shows low activity in vitro and a sedimentation coefficient 9S which is characteristic of immature core polymerase. In this paper we describe a mutation designated opr1 which suppresses RNA polymerase subunit overproduction. The mutation was found among Ts+ revertants of the Ts double mutant carrying a rpoC1 mutation and a rif-r rpo B251 mutation. Opr1 is closely linked to the original rpo mutations and shows complete trans-dominance. Although opr1 seems to affect RNA polymerase, it does not suppress the accumulation of immature 9S RNA polymerase and does not restore the activity of the RpoC1 mutant enzyme. This and other results of a comparison of strains carrying different combinations of rpoC1, rpoB251 and opr1 mutations suggest that neither inhibition of total RNA and protein synthesis, nor the low RNA polymerase activity in vitro, nor the apparent defects in enzyme maturation, nor the enzyme degradation observed at 42°C are responsible for the overproduction in RpoC1 strains.  相似文献   

18.
Summary Crude protein extracts from single seeds of nondomesticated Mexican bean accessions were analysed by SDS polyacrylamide gel electrophoresis for variability in phaseolin protein. Six new phaseolin types; M1, M2, M3, M4, M5, M6, which contained polypeptides within the same range of molecular weights (51,000 to 45,000 daltons) as occur in the S, T and C phaseolin types of cultivated beans were identified. No T and C types were found among the non-domesticated Mexican accessions, and the S type occurred in less than 7% of the seeds screened. Genetic analyses of F2 progenies from crosses between Sanilac (S), and five of the M types showed that each M phaseolin phenotype was allelic to the S type and expressed codominantly.  相似文献   

19.
Summary In a previous paper, two types of cyclic nucleotide-dependent protein kinases, namely cGMP dependent G-kinase and cAMP dependent A-kinase, in silkworm eggs has been reported (Takahashi et al. 1975; Takahashi 1976). One of these, G-kinase, has now been purified 2400-fold by means of ammonium sulfate fractionation, chromatography on hydroxylapatite, DEAE cellulose, and gel filtration.Some of the properties of the enzyme are described. The enzyme is highly dependent on cGMP; it is strongly inhibited by GTP in a noncompetitive manner not only for ATP but also for cGMP. GTP was found to be highly inhibitory on G-kinases from various tissues of the silkworm, but did not inhibit the A-kinase.Incubation of the egg extract with [-32P]ATP and Mg2+ led to the formation of three major32P-labelled proteins, with molecular weights of 42.000, 70.000 and 180.000 as analyzed by SDS polyacrylamide gel electrophoresis. Two of them corresponded to the subunits of vitellin.The silkworm vitellin was effectively phosphorylated both by the highly purified G-kinase and by the A-kinase. It is concluded that the G-kinase is involved in the phosphorylation of vitellin in developing silkworm eggs.Abbreviations cAMP adenosine 35-monophosphate - cGMP guanosine 35-monophosphate - A-kinase adenosine 35-monophosphate-dependent protein kinase - G-kinase guanosine 35-monophosphate-dependent protein kinase - MIX 1-methyl-3-isobutylxanthine  相似文献   

20.
Benzyladenine (BAP) uptake and metabolism were characterized during the key stages of shoot organogenesis in leaf explants of Petunia MD1. Using leaf explant transfer experiments, it was shown that exposure to 2.2 M BAP for 6, 8 or 10 days induced shoot formation on 27, 80 and 100% of the explants respectively, with a concomitant increase in the number of shoots per explant. BAP uptake and metabolism were characterized in leaf explants after 1, 3, 6 or 10 days exposure to [3H]BAP or 10 days exposure plus an additional 2 days on basal medium (10+2). BAP and 9--D-ribofuranosyl-BAP ([9R]BAP) were detected at days 1 and 3 only. Therefore, the BAP free base was not detectable during the shoot induction period between days 6 and 10, as defined by leaf transfer experiments. The BAP ribotide pool was largest on day 1 and decreased to day 10+2. It is possible that the BAP ribotide pool provided either the active cytokinin itself or acted as a short-term storage form for the active cytokinin in petunia shoot organogenesis. Other metabolites detected in petunia leaf tissue included 7--D-glucopyranosyl-BAP ([7G]BAP), 9--D-glucopyranosyl-BAP ([9G]BAP) and an unidentified metabolite C.Abbreviations BAP benzyladenine - [7G]BAP 7--D-glucopyranosyl-BAP - [9G]BAP 9--D-glucopyranosyl-BAP - [9R]BAP 9--D-ribofuranosyl-BAP - [9R-5P]BAP 5-monophosphate of [9R]BAP - [9R-5PP]BAP 5-diphosphate of [9R]BAP - [9R-5PPP]BAP 5-triphosphate of [9R]BAP - TEA Triethylamine This research was supported in part by NSF Grant DCB-8917378 to J.D.C. and USDA-CRGO Grant 89-37261-4791 to T.J.C.  相似文献   

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