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1.
    
The distribution and use of the element kit as terminal part of the song of Chaffinches was studied in 16 . The frequency of occurrence of the kit was dependent on individual and on song types, and the kit was omitted significantly more often then any other part of the song pattern. The specific character of the kit as a terminal element, possible proximate factors for its occurrence, and the question whether it is a hetero-specific imitation are discussed.  相似文献   

2.
The production of five chain variants (Hb G-Georgia, Hb St. Luke's, Hb Lloyd, Hb Montgomery, and Hb G-Philadelphia) in heterozygotes was evaluated through hematological observations, hemoglobin quantification, and biosynthetic studies. All heterozygotes for Hb St. Luke's and Hb Lloyd and most heterozygotes with Hb G-Georgia and Hb Montgomery had normal hematology and average / values of about 1.1. They were assigned a normal genotype (G/), although the proportions of Hb St. Luke's and Hb G-Georgia were low (10 to 13%) and those of Hb Lloyd and Hb Montgomery twice as high (20%). Data from short-term incubations confirmed this genotype for some of these heterozygotes. Isolated Hb St. Luke's and Hb G-Georgia gave low G/ values (0.2 and 0.3) indicating that these Hb variants were defective at the level of Hb assembly. Isolated Hb Montgomery and Hb G-Philadelphia, however, gave higher G/ values of 0.6 and 0.8, respectively. A second type of variability existed among Hb G-Georgia (20 vs. 13%), Hb Montgomery (28 vs. 20%), and Hb G-Philadelphia (47 vs. 34%) heterozygotes, in whom the levels of Hb G differed. The occurrence of higher levels of these three chain heterozygosities was associated with hematological or biosynthetic evidence of a mild or moderate chain deficiency due to an -thalassemia-2 heterozygosity (G/0 or 0G/) or a homozygosity (0G/0), respectively.This study was supported in part by USPHS Research Grants HLB-05168 and HLB-15158.  相似文献   

3.
The complete amino acid sequence of the A-chain of major hemoglobin component from Cuckoo (Eudynamys scolopaceae) is presented. Separation of the polypeptide subunits was achieved by ion exchange chromatography in the presence of 8 M urea. The sequence was studied by automatic Edman degradation of the native chain and its tryptic fragments in a gas-phase sequencer. Comparison with other avian hemoglobins shows residues 21, 30, 96, 110, and 114 as being specific to Cuckoo. The functional significance of these is discussed.  相似文献   

4.
Summary The leu-3/-IPM (-isopropylmalate) regulatory system, previously shown to control several genes of leucine, isoleucine, valine, and histidine biosynthesis, appears likely to be involved also in the regulation of overall RNA and protein synthesis in Neurospora. Upon addition of -IPM the synthesis of all major species of stable RNA was found to be transiently inhibited by approximately 50%. A similar reduction was observed in overall protein synthesis. The inhibition was dependent in both cases on a functional leu-3 gene product, in conformance with previously established patterns of -IPM dependent gene regulation. The overt resemblance of the phenomenon described here to the stringent response of bacteria is noted but neither the mechanism of inhibition nor the precise role of -IPM in the process has been established.  相似文献   

5.
The cyclic 35-nucleotide phosphodiesterase D3 was purified from Sinorhizobium fredii MAR-1. The native enzyme had a molecular weight of approximately 44.5kDa and a subunit molecular weight of approximately 21kDa as judged by SDS-gel electrophoresis. The pH optimum of the enzyme for the hydrolysis of cyclic AMP was approximately 6.0 with both acetate and Tris-maleate buffers. The optimum temperature for hydrolysing cyclic AMP was approximately 50C. No metal ion was required for activity and EDTA up to 2.5mM did not markedly affect the enzyme. However, methylxanthines, adenine and adenosine as well as 5-AMP, ATP, ADP and metal ions like Zn2+, Fe2+, Pb2+, Al3+ and Fe3+, were strongly inhibitory at 2.5mM.The D3 enzyme could hydrolyse both cyclic AMP and cyclic GMP with the apparent K m for cyclic AMP of approximately 0.23M.  相似文献   

6.
Summary The fermentation of an equimolar mixture of glucose and fructose into ethanol and sorbitol by a glucose negative mutant ofZymomonas mobilis was monitored. The results were analyzed using a recently described method based on polynomial fitting and calculation of intantaneous and overall parameters. These parameters described well the physiology of this mixed-substrate mixed-product fermentation. Growth of the mutant was greatly inhibited on this medium. Fructose was quantitatively converted into sorbitol while glucose was oxidized into gluconic acid .This latter product was utilized as substrate for cell growth and ethanol production.Nomenclature X biomass concentration, g/l - S total sugar concentration, g/l - Glu glucose concentration, g/l - Fru fructose concentration, g/l - Sor sorbitol concentration, g/l - P ethanol concentration, g/l - t fermentation time, h - specific growth rate, h-1 - qs specific sugar uptake rate, g/g.h - qG specific glucose uptake rate, g/g.h - qF specific fructose uptake rate, g/g.h - qP specific ethanol productivity, g/g.h - qSor specific sorbitol productivity, g/g.h - YX/S biomass yield on total sugar, g/g - YP/S ethanol yield on total sugar, g/g - YSor/S sorbitol yield on total sugar, g/g - ySor/f sorbitol yield on fructose, g/g - YP/G ethanol yield on glucose, g/g  相似文献   

7.
Summary The relative contents of Na,K-ATPase subunit mRNAs in rat renal cortex; ventricular myocardium, skeletal muscle (hind limb), liver and brain (cerebrum) were measured. Expressed per unit DNA, mRNA1 content was 2-fold greater in the kidney and brain as compared to either heart, skeletal muscle or liver. The hierarchy of mRNA2 expression was brain > skeletal muscle > heart, whereas mRNA3 was restricted to brain. Betal subunit mRNA content in both kidney and brain exceeded the abundance of liver mRNA 1 by 7-fold. In all tissues examined, the combined abundances of the alpha subunit mRNAs exceeded the content of mRNA 1 The hierarchy of Na,K-ATPase activity expressed per unit. DNA was brain > kidney > skeletal muscle = heart > liver. The sum of mRNA as well as mRNA 1 content, expressed per g of tissue, was highest in brain and kidney. A statistically significant correlation between mRNA 1 content and Na,K-ATPase activity was evident.  相似文献   

8.
Summary A distinction between the chemical composition of ultrastructurally modified regions and the rest of the cell wall (canals) of the yeast Schwanniomyces occidentalis was shown by cytochemical staining of cell wall polysaccharides. The formation of canals was induced by cultivation of yeasts on hydrocarbons and was parallelled by the enhancement of -glucosidase, -glucanase and -mannosidase activities which were all capable of degrading cell wall polysaccharides. The presence of cycloheximide prevented canal formation. We assume that these hydrolases modified definite cell wall regions transforming them into canals.  相似文献   

9.
A mouse monoclonal antibody (87.5) against Gal1-4Gal has been obtained after immunization with the disaccharide glycosidically coupled to a protein. The specificity was determined by studying its binding to a number of glycoconjugates and oligosaccharides.The antibody which was found to be highly specific for terminal Gal1-4Gal residues is a powerful tool for the detection of this structure in glycoproteins and glycolipids by immunochemicalin vitro methods. It is also useful forin vitro quantification of the free disaccharide.A thin layer chromatographic overlay assay using glycolipids and an immunoperoxidase technique is also described. The antibody 87.5 is used in this assay to identify human uroepithelium glycolipids with terminal Gal1-4Gal residues.Abbreviations Lactosylceramide Gal1-4GlcCer - globotriaosylceramide GbOse3-ceramide, Gal1-4Gal1-4GlcCer - globotetraosylceramide globoside, GbOse4-ceramide, GalNAc1-3Gal1-4Gal1-4GlcCer  相似文献   

10.
Plausible prebiotic conditions for the phosphorylation of nucleosides by inorganic phosphate were reported by Lohrmann and Orgel in 1971. This reaction was carried out on heated dry films and promoted by urea. The major products formed were nucleoside-2:3 cyclicPs; 5-NMPs and other derivatives were also formed. Minor modifications of the Lohrmann and Orgel system have resulted in the preferential formation of 5-NMPs. In this modified system a 2-fold preference for phosphorylation of the 5-OH group over the 3(2)-OH group was observed and the formation of other derivatives was minimized. The small amounts of bis compounds that were formed in this system could be quantitatively removed by selective binding to the mineral hydroxylapatite at moderate ionic strengths. It was also discovered that under hydrolytic conditions there was a 3:1 preference for removal of phosphates attached to the 3-OH group over the 5-OH group. A recycling procedure for obtaining additional 5-NMPs from bis compounds and 3-NMPs is proposed.  相似文献   

11.
The degradation of the phenylcoumaran substructure model compound methyl dehydrodiconiferyl alcohol by the white-rot wood decay fungus Phanerochaete chrysosporium was investigated using culture conditions optimized for lignin oxidation. Initial attack was in the cinnamyl alcohol side chain, which was oxidized to a glycerol structure. This was subsequently converted by loss of the two terminal carbon atoms, C and C, to yield a C-aldehyde structure, which was further oxidized to the C-acid compound. The next detected intermediate, a phenylcoumarone, was produced by double bond formation between C and C, and oxidation of the C-alcohol to an aldehyde group. Further oxidation of C to an acid yielded the next intermediate. The final identified degradation product was veratric acid. No products from the 5-substituted aromatic ring, and no phenolic products, were found. The initial glycerol-containing intermediate was a mixture of the threo and erythro forms, and no optical activity could be found, suggesting that its formation might have involved nonstereospecific C-C epoxidation followed by non-enzymatic hydrolysis of the epoxide.Abbreviations TLC thin layer chromatography - LDA lithium diisopropyl amide - DDQ 2,3-dichloro-5,6-dicyanobenzoquinone - MS mass spectrometry - UV ultraviolet spectroscopy  相似文献   

12.
The effect of estradiol, hydrocortisone and progesterone on 3,20-and 3,17-hydroxysteroid dehydrogenase (HSD) in mutants of Streptomyces hydrogenans was compared to the steroid response of the wild type. Mutants were defective in arginine biosynthesis and/or aerial mycelial formation and lacked both enzymes or only 17-HSD. Some 17-HSD mutants had lost the ability to be induced by estradiol, by progesterone or by both. Some 20-HSD mutants had lost the ability to be induced by hydrocortisone, by progesterone or by both. Non-inducibility of 17-and 20-HSD by progesterone was not co-ordinate. An additional study of the growth phase-dependent enzyme activity of the wild type after induction with estradiol, hydrocortisone and progesterone was performed.Non-standard abbreviations 17-HSD 3,17-Hydroxysteroid dehydrogenase (EC 1.1.1.51) - 20-HSD 3,20-hydroxysteroid dehydrogenase (EC 1.1.1.53) - AO acridine orange - EBr ethidium bromide - EMS ethyl methanesulfonate - MNNG N-methyl-N-nitro-N-nitrosoguanidine  相似文献   

13.
A diffusible sex-specific substance called substance-I (S-I) was isolated from culture filtrate of type strains of the yeast Saccharomyces cerevisiae. The isolated S-I, an oligopeptide, induced sexual cell agglutinability in inducible a type strains and enhanced the agglutinability in constitutive a type strains. The induction of sexual agglutinability was detected in 30 min and reached maximum in 90 min, when 0.2 g/ml of S-I was added to inducible a type cells. The a type-specific factor responsible for sexual cell agglutination, called a type agglutination factor (aAF), was shown to be produced during the induction or the enhancement of agglutinability of a type cells by S-I. The aAF produced in response to S-I was not different in the susceptibility to proteolytic enzymes and disulfide-cleaving agents from those produced constitutively in the absence of S-I.  相似文献   

14.
Zusammenfassung Die Behandlung der drei Hopfensorten Saazer, Hüller Anfang und Hallertauer mit Gibberellinsäure ergab eine Verminderung des 1000-Doldengewichtes, aber eine Zunahme der Dolden je Pflanze.Beim Hüller Anfang und beim Hallertauer nahm der Gehalt an Alpha-Säuren durch die Behandlung ab; bei der Saazer Sorte blieb er gleich bis auf die Dosierung 10 ppm, 2 x, wodurch eine Erhöhung eintrat.Bei der Handbonitierung der Dolden ergab sich eine Wertminderung besonders hinsichtlich Zapfenwuchs, Lupulingehalt und Feinheit des Aromas, wozu beim Hüller Anfang noch eine starke Doldenverlaubung hinzukommt.Die Entwicklungsdauer der ganzen Pflanze wird unter dem Einfluß von Gibberellinsäure in die Länge gezogen, so daß die Doldenreife verzögert wird. Aus frühen und mittelfrühen werden dadurch mittelfrühe bzw. späte Hopfensorten.Die weibliche Blüte wird in ihrer Ausbildung teilweise gehemmt; im Extremfall führt dies zu einer Unterdrückung aller Blütenorgane mit der Tendenz zur Rückführung des Blütenstandes in den ursprünglichen beblätterten Laubsproß. Die Kreuzungssorte Hüller Anfang reagierte außerdem mit der Bildung monözischer Blütenstände. Die Entstehung der Monözie wird diskutiert.Die unterschiedlichen Reaktionen auf die Gibberellinsäurebehandlung bei den einzelnen Sorten sind auf die verschiedenen Entwicklungszustände zum Zeitpunkt der Behandlung zurückzuführen.
The influence of gibberellic acid on the flower and cone development in hop (Humulus lupulus L.)
Summary The treatment of the three hop-varieties Saazer, Hüller Anfang and Hallertauer with gibberellic acid caused a decrease of the 1000-cone weight, but an increase in cones of each plant.With Hüller Anfang and Hallertauer there was a decrease in -acid content, in the Saazer variety it remained equal, only when it was treated by the dosage 10 ppm, times two, an icrease in -acid content resulted.The organoleptic valuation of the cones showed a decrease in quality especially in respect to cone size, Jupulin content and delicacy of aroma. In the Huller Anfang variety a high percentage of cock hops resulted also.Under the influence of gibberellic acid the development of the hop plant is prolonged, so that the ripening of cones is retarded. Early and middle-early varieties thus become middle-early and late varieties.The female flower is somewhat retarded in development; in the extreme case this leeds to complete suppression of all flower parts and a tendency to reduce the female inflorescence to the original leaf shoot. Moreover, the hybrid variety Hüller Anfang formed monoecious plants. The origin of monoecious plants is discussed.The different reactions to treatment with gibberellic acid of the several varieties are caused by the differing stages of plant development at the time of treatment.
  相似文献   

15.
In contrast to the well-characterized spinach ( Spinacea oleracea) chloroplast ATP synthase (CF1–CFo), the properties of the chloroplast ATP synthase from pea (Pisum sativum ) have not been as intensively studied. Preliminary data suggested that the regulatory properties of the two enzymes differ. In the absence of activating treatments the ATPase activity of pea thylakoids in the dark was higher than that in spinach thylakoids. When assayed in the presence of sulfite, the MgATPase activity of pea thylakoids was inhibited to a maximum of 67% by tentoxin, indicating that the dark ATPase activity is in part catalyzed by CF1–CFo. The ATPase activity of purified pea CF1 was also higher than that of spinach CF1 in the absence of activating treatments. These differences could result from the different regulatory properties of the pea or subunit or both. The pea subunit was less effective in binding to or inhibiting the ATPase activity of pea o r spinach CF1 deficient in (CF1-). Spinach inhibited the ATPase activity of pea CF1- at lower concentrations than pea . The gene encoding the pea subunit was cloned and over-expressed. Recombinant pea did not restore low proton permeability to spinach thylakoid membranes reconstitituted with spinach CF1-, although pea was effective when tested with pea thylakoids reconstitituted with pea CF1-. These results confirm earlier suggestions that the C-terminal region of is important in -CF1 and -CFo interactions.  相似文献   

16.
From the gene library constructed with the chromosomal DNA of 6-mercaptoguanosine (MGS)-resistant strain Brevibacterium ammoniagenes IPR-1, a DNA fragment which conferred MGS-resistance to the wild-type strain B. ammoniagenes ATCC6872 was cloned. The purF gene encoding 5-phosphoribosyl-1-pyrophosphate amidotransferase was identified from this fragment and its nucleotide sequence was determined. Wild type purF gene was also cloned by polymerase chain reaction using chromosomal DNA of ATCC6872 as the template and its sequence was determined. Two nucleotides, 583 A and 1065 A, of MGS-resistant purF gene had been changed from 583 G and 1065 G by mutagenesis, respectively. Both changes at position 583 and 1065 were proved to be responsible for MGS-resistance by site-directed mutagenesis.  相似文献   

17.
Summary A series of man-Chinese hamster and man-mouse somatic cell hybrids was investigated to study the localization of the genes coding for the human lysosomal enzyme -galactosidase (EC 3.2.1.23) and for its protective protein. Using a monoclonal antibody, raised against human placental -galactosidase, it was observed that the structural locus for the -galactosidase polypeptide is located on chromosome 3. The nature of the involvement of chromosome 22 in the expression of human -galactosidase was elucidated by metabolic labelling of the hybrids with radioactive amino acids, immunoprecipitation with monoclonal and polyclonal antibodies against -galactosidase, followed by analysis via gel electrophoresis and fluorography.The data show that the presence of chromosome 22 coincides with the presence of a 32 kd protein. This polypeptide, the protective protein was previously shown to be intimately associated with human -galactosidase. In addition, the protective protein was found to be essential for the in vivo stability of -galactosidase by aggregating -galactosidase monomers into high molecular weight multimes. Both chromosome 3 and 22 are therefore necessary to obtain normal levels og -galactosidase activity in human cells.  相似文献   

18.
An -glucosidase cDNA clone derived from barley aleurone tissue was expressed in Pichia pastoris and Escherichia coli. The gene was fused with the N-terminal region of the Saccharomyces cerevisiae -factor secretory peptide and placed under control of the Pichia AOX1 promoter in the vector pPIC9. Enzymatically active, recombinant -glucosidase was synthesized and secreted from the yeast upon induction with methanol. The enzyme hydrolyzed maltose > trehalose > nigerose > isomaltose. Maltase activity occurred over the pH range 3.5–6.3 with an optimum at pH 4.3, classifying the enzyme as an acid -glucosidase. The enzyme had a Km of 1.88 mM and Vmax of 0.054 µmol/min on maltose. The recombinant -glucosidase expressed in E. coli was used to generate polyclonal antibodies. The antibodies detected 101 and 95 kDa forms of barley -glucosidase early in seed germination. Their levels declined sharply later in germination, as an 81 kDa -glucosidase became prominent. Synthesis of these proteins also occurred in isolated aleurones after treatment with gibberellin, and this was accompanied by a 14-fold increase in -glucosidase enzyme activity.Abbreviations: AGL, barley seed -glucosidase; rAGL, recombinant barley seed -glucosidase; BMGY, buffered glycerol-complex medium; BMMY, buffered methanol-complex medium; GA, gibberellic acid; UTR, untranslated region.  相似文献   

19.
Summary Genetic diversity among ten varieties of spring wheat used as parents in a diallel cross was assessed through multivariate analysis (D2-statistics) and then related to heterosis and SCA effects of their hybrids. The parents fell into three groups. Group I contained the varieties, Nobre, Girua and Carazinho; group II contained Sonalika, Lyallpur and Pitic 62 and group III contained Indus 66, Balaka, Sonora 64rs and MSl. The varieties of group I were good general combiners, while the varieties of group III were poor combiners. Significant heterotic and SCA effects for yield and yield components were observed in the hybrids of the parents belonging to different groups but not in the same group. Genetic divergence between the parents had a positive relationship with heterosis and SCA effects of the hybrids.  相似文献   

20.
The distribution of cysteine oxidase (CO) and cysteine sulfinate decarboxylase (CSD) was examined in 12 regions of the rat central nervous system (CNS). The distribution of CO activity, expressed as mol of cysteine sulfinate formed per h per g, was the following: hypothalamus, superior and inferior colliculi, 94–99 mol/h/g; olfactory bulbs, cerebral cortex, striatum, and hippocampus, 44–51 mol/h/g; cerebellum, 71 mol/h/g; pons-medula and spinal cord, 94 and 60 mol/h/g, respectively. The distribution of CSD activity expressed as mol of cysteine sulfinate decarboxylated per h per g was the following: hypothalamus and colliculi, 14–21 mol/h/g; olfactory bulbs, cerebral cortex, striatum, hippocampus, and cerebellum, 8–13 mol/h/g; pons-medulla, 7.3; and spinal cord, 3.6 mol/h/g. No CSD activity was detected in sciatic nerve. The subcellular distribution of CO and CSD activities was studied in hypothalamus, colliculi, and cerebral cortex. CO activity was localized in synaptosomes, mitochondria, and microsomes. CSD was primarily confined to the crude mitochondrial fraction and after subfraction, recovered mainly in the synaptosomal fraction.  相似文献   

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