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1.
R Lamed  U Mrwa 《Experientia》1976,32(9):1221-1222
Heavy meromyosin subfragment-1 (HMM S-1) was prepared by papain digestion of arterial myosin or actomyosin and was purified by agarose-ATP affinity chromatography. Proteolysis of crude arterial myosin suspensions was preceded by solubilization. HMM-S-1 thus obtained consisted mainly of a 90,000 dalton polypeptide and fully retained the K+- and Ca2+-ATPase of the parent myosin. Its affinity to agarose-ATP was comparable to that of skeletal muscle HMM S-1.  相似文献   

2.
Summary The effects of various divalent cations, Ca2+, Mg2+ and Mn2+ on the intrinsic fluorescence of heavy meromyosin (HMM) and myosin 5,5-dithio-bis-(2-nitrobenzoate) DTNB-light chain of rabbit striated muscle, are compared. At pH 6.4, the fluorescence change induced by the metal ions is present only in the isolated light chain and disappears in HMM, thus indicating an interaction between the heavy and light chains with respect to the binding of the metal ions. Whereas Mg2+ binds more strongly than Ca2+ to myosin, this order is reversed in the case of the DTNB-light chain.  相似文献   

3.
Summary Sedimentation and diffusion coefficients, partial specific volume, intrinsic viscosity, ATP-ase activity and molecular weight of cardiac myosin from calf hearts were determined. The values agree well with the results ofMueller et al.4 for cardiac myosin of the dog, and are not essentially different from values reported for skeletal myosins.1   相似文献   

4.
The uptake ofL-arginine into purified rat brain synaptosomes was investigated with respect to time and various concentrations ofL-[3H] arginine. Specific uptake was found to be linear with time for up to 5 min of incubation at 37°C. Electrolytes, including sodium chloride, potassium chloride, magnesium chloride and calcium chloride, inhibited uptake of 3 ML-arginine, and the inhibitory effect increased with increased electrolyte concentration under constant osmolarity. It was found thatL-arginine was transported into synaptosomes by two uptake components — a high affinity component (3.5 M) and a low affinity component (100 M). These two components were similar to the Ly+ system because of their extreme sensitivity to inhibition byL-lysine andL-ornithine but were distinguishable from each other by kinetic analysis of the uptake data and by their relative sensitivity to inhibition by several amino acids.  相似文献   

5.
Summary In this paper the correlation between phosphate incorporation into the regulatory light chain of myosin by a Ca2+-dependent myosin light chain kinase, and the Ca2+-sensitive ATPase activity and superprecipitation behaviour of arterial actomyosin, is described.Acknowledgment. The financial support of the Deutsche Forschungsgemeinschaft (SFB 90) is gratefully acknowledged.  相似文献   

6.
Electron-microscopic mapping of the hinge region of myosin   总被引:1,自引:0,他引:1  
Summary The trypsin-sensitive sites in the labile hinge region of the myosin molecule are located with heightened accuracy (±2 nm) by electron microscopy as lying at 70, 85, 95, and 103 nm from the C-terminus of the rod section of the molecule.I thank Dr.Michael Young for valuable advice and encouragement, Drs.Jerome Gross andRomaine R. Bruns for use of their electron microscope, and Mrs.Muriel H. Blanchard for excellent technical assistance. This work was supported by the American Heart Association, The John A. Hartford Foundation, Inc., and the National Institutes of Health.  相似文献   

7.
Zusammenfassung Während der Biosynthese von Cholesterol mit homogenisierter Rattenleber wird [2-14C] des Glycins viel besser eingebaut als [1-14C].Saccharomyces cerevisiae produziert radioaktives Squelen (ausser Ergosterol mit Radioaktivität des Ringsystems) mit [2-14C] Glycin und mit [3-14C] Serin, aber nicht mit [1-14C] Glycin.

Studies on Biosynthesis. Part VI. For Part V, seeA. K. Bose, K. S. Khanchandani andB. L. Hungund, Experientia,27, 1403 (1971). b) Presented at the 164th National Meeting of the American Chemical Society, New York, August, 1972.

The support of this research by Stevens Institute of Technology and Sandoz Foundation is gratefully acknowledged. We wish to thank Drs.P. T. Funke, M. S. Manhas, P. K. Bhattacharyya, M. Anchel andH. Levey for valuable discussions and help with some of the experiments.  相似文献   

8.
Zusammenfassung Die Trennung von schnellen und langsamen Komponenten von S-100-Protein wurde durch Disk-Elektrophorese mit einem kontinuierlichen Puffersystem ausgeführt und die Anwendungen auf Mikroelektrophorese des sauren Proteins von kleinen isolierten Mengen der Hirnsubstanzen (1 g Feuchtgewicht) dargestellt.

The authors with to thank MissT. Tanaka for her skilful technical assistance.  相似文献   

9.
The endocannabinoid system and endocannabinoid receptor-driven modulation of glutamate release were studied in rat brain cortex astroglial gliosomes. These preparations contained the endocannabinoids N-arachidonoylethanolamine (anandamide) and 2-arachidonoylglycerol, as well their major biosynthetic (N-acyl-phosphatidylethanolamines-hydrolyzing-phospholipase D and diacylglycerol-lipase) and catabolic (fatty acid amide-hydrolase and monoacylglycerol-lipase) enzymes. Gliosomes expressed type-1 (CB1R), type-2 (CB2R) cannabinoid, and type-1 vanilloid (TRPV1) receptors, as ascertained by Western blotting and confocal microscopy. Methanandamide, a stable analogue of anandamide acting as CB1R, CB2R, and TRPV1 agonist, stimulated or inhibited the depolarization-evoked gliosomal [3H]d-aspartate release, at lower and higher concentrations, respectively. Experiments with ACEA (arachidonyl-2′-chloroethylamide), JWH133 ((6aR,10aR)-3-(1,1-dimethylbutyl)-6a,7,10,10a-tetrahydro-6,6,9-trimethyl-6H-dibenzo[b,d]-pyran) and capsaicin, selective agonists at CB1R, CB2R and TRPV1, respectively, demonstrated that potentiation of [3H]d-aspartate release was due to CB1R while inhibition to CB2R and TRPV1 engagement. These findings were confirmed by using selective receptor antagonists. Furthermore, CB1R activation caused increase of intracellular IP3 and Ca2+ concentration, suggesting an involvement of phospholipase C.  相似文献   

10.
Summary The PGE2-induced cyclic AMP accumulation in the rat anterior pituitary in vitro is inhibited by [desamino1]-, [desamino1] [descarboxy14] and [d-Lys4]-somatostatin similarly to somatostatin, while the [descarboxy14]-somatostatin exhibits reduced activity; [d-Lys9]-somatostatin is ineffective at a higher concentration.The authors acknowledge the technical assistance ofG. Alexander. F. Bellini, D. Mangerel andJ. Rochon and thank Dr.G. Schilling and his associates for the analytical data.  相似文献   

11.
Summary Referring to a paper published in this review1, two further processes are described which might produce the supplementary energy necessary to start tornado formation according toKoschmieder's theory1. Firstly, in the air bordering on, and forced upward by, a cumulonimbus cloud, additional upward acceierations may develop conforming toNormand's considerations2, if the surrounding atmosphere is in a state of latent conditional instability. Secondly, upward accelerations may suddenly originate within the cumulo-nimbus itself if the supercooled water drops freeze at once (mixing stage)3. A satisfactory solution of the problem can of course only be given by quantitative and not purely qualitative considerations.  相似文献   

12.
Conclusion 79. This study of the interaction between mechanics and differential geometry does not pretend to be exhaustive. In particular, there is probably more to be said about the mathematical side of the history from Darboux to Ricci and Levi Civita and beyond. Statistical mechanics may also be of interest and there is definitely more to be said about Hertz (I plan to continue in this direction) and about Poincaré's geometric and topological reasonings for example about the three body problem [Poincaré 1890] (cf. also [Poincaré 1993], [Andersson 1994] and [Barrow-Green 1994]). Moreover, it would be interesting to find out how the 19th century ideas discussed here influenced the developments in the 20th century. Einstein himself is a hotly debated case.Yet, despite these shortcommings, I hope that this paper has shown that the interactions between mechanics and differential geometry is not a 20th century invention. Klein's view (see my Introduction) that Riemannian geometry grew out of mechanics, more specifically the principle of least action, cannot be maintained. On the other hand, when Riemannian geometry became known around 1870 it was immediately used in mechanics by Lipschitz. He began a continued tradition in this field, which had several elements in common with the new view of mechanics conceived by the physicists and explicitly carried out by Hertz.Before 1870 we found only scattered interactions between differential geometry and mechanics and only direct ones for systems of two or three degrees of freedom. For more degrees of freedom the geometrical ideas were in some interesting cases taken over by analogy, but these analogies did not lead to formal introduction of geometries of more than three dimensions.  相似文献   

13.
Summary In the in vitro experiments described above neither the hormone of the left ovary nor that secreted by the rudimentary right gonad brought about the regression of the right Müllerian duct of the female chick embryo. In castration experiments, this naturally occurring phenomenon had been found to depend either on the right gonad (Huijbers 4) or on both the right and left gonads (Wolff 1–3).  相似文献   

14.
Summary The production of antibodies against amanitins is described. By means of these antibodies, a radioimmunoassay was developed which allows detection of as little as 0.5 ng of amanitins in 1 ml of serum. By this method, the clearance of α-amanitin from the blood of poisoned mice was measured. Acknowledgments. We thank ProfessorT. Wieland and Dr.H. Faulstich (Heidelberg) for their generous gift of β-amanitin and [3H]O-methyl-demethyl-γ-amanitin. This work was supported by grants from C.N.R., Rome.  相似文献   

15.
Summary By incubation of human erythrocyte ghosts with cholesterol oxidase (EC 1.1.3.6) part of the cholesterol of the membrane is replaced by 4-cholesten-3-one. This alteration in the sterol composition is accompanied by an inhibition of the (Na+, K+) ATPase of the erythrocyte membrane.Acknowledgments. This study was supported by the Deutsche Forschungsgemeinschaft Bonn-Bad Godesberg and the Sonderforschungsbereich 90 of the University of Heidelberg. We thank Mr.J. Schmidt and MissI. Geldmacher for skilful technical assistance.  相似文献   

16.
Summary The incorporation of tyrosine-2-14C-15N into xanthocillin X (I) byPenicillium notatum Westling has been investigated showing that nitrogen of the isocyano groups originates from tyrosine, which is incorporated as C6-C2-N-unit.

1. Mitteilung:H. Achenbach undH. Grisebach, Z. Naturforsch.20b, 137 (1965).  相似文献   

17.
Summary Ca2+-stimulated ATPase activity of sarcoplasmic reticulum (SR) preparations is activated after a short period of preincubation at temperatures between 40 and 45°C, but for temperatures higher than 48°C pronounced denaturation is observed. Heat denaturation is decreased if Mg2+ or K+ are present during heat treatment.Acknowledgments. This work was supported by research grants from Instituto de Alta Cultura (Grant No. CB/2) and the Calouste Gulbenkian Foundation. We are grateful to Drs.A. P. Carvalho andV. M. C. Madeira for many discussions and suggestions during the course of this work.  相似文献   

18.
Summary It has been shown that the leaves ofPl. acutifolia incorporate acetate-1-14C and mevalonate-2-14C specifically for the formation of the aglycone moiety of plumieride.

Wir danken dem Schweizerischen Nationalfonds sehr für die Unterstützung der Arbeit, Herrn Dr.J. Würsch (F. Hoffmann-La Roche & Cie., Basel) für markiertes Mevalonsäure-lakton und Herrn Prof.D. Arigoni (Zürich) für interessante Diskussionen.  相似文献   

19.
Zusammenfassung Es wird gezeigt, dass Cholesterin-H3, nach Behandlung von besonders gereinigtem Handelscholesterin mit Tritium entsprechend der Vorschrift vonWilzbach, bei sechsmal wiederholter Bromierung nachFieser frei von Cholestanol-H3 erhalten wird. In so gereinigtem Cholesterin-H3 ist der schwere Wasserstoff gleichmässig über alle wasserstofftragenden Kohlenstoffatome verteilt.

This work was supported by an Institutional Grant No. P-108A of the American Cancer Society and by a Grant No. G-7477 of the National Science Foundation. The authors are grateful to Dr.M. Gut of this Institute for theWilzbach treatment of cholesterol.  相似文献   

20.
At the end of the 19th century Oliver Heaviside developed a formal calculus of differential operators in order to solve various physical problems. The pure mathematicians of his time would not deal with this unrigorous theory, but in the 20th century several attempts were made to rigorise Heaviside's operational calculus. These attempts can be grouped in two classes. The one leading to an explanation of the operational calculus in terms of integral transformations (Bromwich, Carson, Vander Pol, Doetsch) and the other leading to an abstract algebraic formulation (Lévy, Mikusiski). Also Schwartz's creation of the theory of distributions was very much inspired by problems in the operational calculus.  相似文献   

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