Métabolisme intracellulaire et extracellulaire de l'acide 3-indolylacétique dans les cultures aseptiques ou non aseptiques de pointes de racine du Pisum sativum

1968 ◽  
Vol 46 (8) ◽  
pp. 969-978 ◽  
Author(s):  
G. F. Collet
Keyword(s):  
Absorption Spectrum ◽  
Pisum Sativum ◽  
Indoleacetic Acid ◽  
Specific Activity ◽  
High Specific Activity ◽  
Ultraviolet Absorption Spectrum ◽  
Root Tips ◽  
Pea Seedlings ◽  
Oxidase Inhibition ◽  
Layer Chromatography

Studies on indoleacetic acid (IAA) metabolism with root tips of 3-day-old pea seedlings were carried out by thin-layer chromatography and 14C-labelled auxin of high specific activity at 10−6 M. After 16-h incubation, five metabolites of IAA could be recognized in the tissues and two in solution; one metabolite was identified as o-formamidoacetophenone from its chromatographic Rf and ultraviolet absorption spectrum. Under sterile conditions the rate of breakdown of IAA is higher in the medium than under nonsterile conditions (even after removal of the tissues). We noted, too, a decrease of the action of IAA on the growth. The decreased activity of solution under nonsterile conditions is believed to be due to the production of oxidase inhibition by microorganisms.

HALF-LIFE OF OXYTOCIN IN BLOOD OF PREGNANT AND NON-PREGNANT WOMEN

1969 ◽  
Vol 61 (3) ◽  
pp. 425-431 ◽  
Author(s):  
Gunnar Rydén ◽  
Ingvar Sjöholm
Keyword(s):  
Pregnant Women ◽  
Specific Activity ◽  
High Specific Activity ◽  
First Trimester ◽  
Second Trimester ◽  
Reverse Effect ◽  
Secretory Phase ◽  
Proliferative Phase ◽  
Menstruating Women ◽  
Layer Chromatography

ABSTRACT Using tritium-labelled oxytocin with a high specific activity, the halflife in the blood and the urinary excretion of intravenously injected oxytocin were followed in the female. The following groups of patients were studied: normally menstruating women during different phases of the menstrual cycle, women using a combination of gestagenic and oestrogenic hormones for oral contraception, and pregnant women in the first and second trimester. The pregnant women were admitted to the hospital for legal abortion in the 10th–20th week of gestation. In the proliferative phase, t½ was 272 seconds (n = 14), in the secretory phase 221 seconds (n = 5), and in women using oral contraceptives 199 seconds (n = 10). In pregnant women during the first trimester, t½ was 178 seconds (n = 6). The corresponding value in women examined during the 14th–17th weeks and during the 18th–20th weeks of gestation was 295 seconds (n = 6) and 282 seconds (n = 6), respectively. T½ was also determined within 24 h of abortion in patients in the second trimester, where the abortion was induced by intra-amniotic instillation of 50% glucose. In all cases a decrease in t½ was found. The decrease was most marked in women during the 18th–20th weeks of gestation. Altogether 25–50% of the radioactivity injected was recovered in the urine from pregnant women within 3 h of the injection. Thin-layer chromatography of the urine did not reveal the presence of any intact oxytocin. The results demonstrate that the disappearance of oxytocin from the blood seems to be influenced by the sex hormones. Thus, an oestrogendominated stage shows a lower disappearance rate, whereas gestagens produce the reverse effect. The pronounced decrease in t½ in pregnant women immediately after abortion might be due to a change to a more progesterone-dominated stage induced by the death of the foetus, or by an alteration in the affinity of oxytocin to the myometrium.

In vivo preparation of [32P]cAMP and thin-layer chromatography of cAMP-related compounds

1979 ◽  
Vol 57 (11) ◽  
pp. 1281-1283
Author(s):  
Hiroshi Yamazaki ◽  
Kwok-Luen Leung ◽  
Ann D. E. Feaser
Keyword(s):  
Wild Type Strain ◽  
Radiochemical Purity ◽  
Specific Activity ◽  
High Specific Activity ◽  
Alumina Column ◽  
Alumina Column Chromatography ◽  
Camp Metabolism ◽  
Layer Chromatography ◽  
Related Compounds

A simple and rapid method for preparing [32P]adenosine 3′,5′-cyclic monophosphate (cAMP) is described. A culture of an Escherichia coli mutant which excretes cAMP about 150 times faster than does a wild-type strain was incubated overnight with [82P]orthophosphate of high specific activity (e.g., 4000 Ci/mol (1 Ci = 37 GBq)). The [32P]cAMP which accumulated extracellularly was then purified to 99.9% radiochemical purity in less than 4 h by adsorption to charcoal and alumina column chromatography. A two-dimensional chromatography system using a PEI-cellulose plate is also described which should prove useful for studying cAMP metabolism with 32P- or 3H-labeled cAMP or ATP.

scholarly journals The Incorporation of Leucine-C14 into Microsomal Particles and other Subcellular Components of the Pea Epicotyl

1959 ◽  
Vol 5 (1) ◽  
pp. 59-68 ◽  
Author(s):  
Paul O. P. Ts'o ◽  
Clifford S. Sato
Keyword(s):  
Specific Activity ◽  
Gradient Centrifugation ◽  
High Specific Activity ◽  
Insoluble Fraction ◽  
Supernatant Fraction ◽  
Group Method ◽  
Pea Seedlings ◽  
Pea Epicotyl ◽  
Hydrolysis Of ◽  
End Group

Incorporation of leucine-C14 into subcellular fractions of the apical section of pea seedlings has been studied as a function of the length of incubation. The specific activity of the microsomes was higher than that of the supernatant for short but not for long incubations, in agreement with observations on other systems. In this developing tissue the nuclei and especially the mitochondria appear to incorporate amino acid very rapidly. An insoluble fraction of the microsome pellet, which is presumably a liponucleoprotein complex, was found to possess, after 1 hour of incubation, a specific activity much greater than that of the purified microsomal particles or the supernatant fraction. Ninety-eight per cent of the leucine-C14 in the purified microsomal particles has been shown to possess bound amino groups, presumably in peptide linkages, by the DNP-end group method. These particles liberate but little peptide or protein of very high specific activity when they are destroyed by removal of Mg or by hydrolysis of RNA. Microsomal particles were fractionated into an RNA fraction and five protein fractions by means of density gradient centrifugation. By this method 95 per cent of the RNA can be separated from 90 per cent of the protein of the particle. Furthermore, the RNA fraction has been shown to contain very little protein of high specific activity. A particular protein fraction which contains the remaining 5 per cent of the RNA, possessed after 1 hour of incubation a specific activity 2 to 9 times higher than the protein of the other fractions.

scholarly journals THE ISOLATION AND PARTIAL CHARACTERIZATION OF THE PYRENOID PROTEIN OF EREMOSPHAERA VIRIDIS

1971 ◽  
Vol 51 (2) ◽  
pp. 499-513 ◽  
Author(s):  
Robert H. Holdsworth
Keyword(s):  
Specific Activity ◽  
Gradient Centrifugation ◽  
Sodium Dodecyl ◽  
High Specific Activity ◽  
Enzymatic Properties ◽  
Ultraviolet Absorption Spectrum ◽  
Fraction I Protein ◽  
Molecular Weights ◽  
Eremosphaera Viridis ◽  
Fraction I

The pyrenoids of Eremosphaera viridis, a green alga, were isolated by density gradient centrifugation and their physical and enzymatic properties were studied. The ultraviolet absorption spectrum of sodium dodecyl sulfate (SDS) extracts of pyrenoids showed a single peak at a wavelength of 277 nm, indicating the presence of protein and the probable absence of nucleic acid. Upon electrophoresis on polyacrylamide gels containing SDS, 16 bands were resolved of which two, together, accounted for 90% of the total protein on the gels. The molecular weights of these two proteins were estimated to be 59,000 and 12,300 and the ratio by weight of the larger to the smaller protein was found to be 2:1. The physical and enzymatic properties of these two proteins were found to closely resemble the properties reported in the literature for the subunits of fraction I protein. Both pyrenoids and fraction I protein are localized in the chloroplast, and both have two principal protein components. The molecular weights and relative ratio of the two pyrenoid components are very similar to those of the two components of fraction I protein. The pyrenoid was found to contain a high specific activity of ribulose-1,5-diphosphate carboxylase which is the same enzymatic activity exhibited by fraction I protein. The presence of ribose-5-phosphate isomerase and ribulose-5-phosphate kinase activities was also noted in pyrenoid preparations. It is suggested that the pyrenoid contains fraction I protein and possibly other enzymes of the Calvin-Bassham carbon dioxide fixing pathway.

Siderophore production by Proteus mirabilis

1984 ◽  
Vol 30 (8) ◽  
pp. 1046-1051 ◽  
Author(s):  
Lisa P. Evanylo ◽  
Solomon Kadis ◽  
James R. Maudsley
Keyword(s):  
Absorption Spectrum ◽  
Proteus Mirabilis ◽  
Biosynthetic Pathway ◽  
Agar Medium ◽  
Ultraviolet Absorption Spectrum ◽  
Gas Chromatograph ◽  
Isolation And Characterization ◽  
Solid Agar ◽  
Layer Chromatography

Studies on the isolation and characterization of Proteus mirabilis siderophores provided no evidence that these bacteria synthesize catechol- or hydroxamate-type siderophores. However, gas chromatograph analysis in conjunction with mass spectroscopy revealed the presence of α-hydroxyisovaleric acid, a previously unknown metabolite. Additional substantiating evidence for the presence of α-hydroxyisovaleric acid in these bacteria was obtained from experiments involving the use of thin-layer chromatography and an ultraviolet absorption spectrum. This compound was found to be capable of removing iron from the synthetic chelator, ethylene-diamine-di-orthohydroxyphenyl acetic acid, and supplying that iron to the bacteria both in a solid agar medium and in a liquid medium. Proteus mirabilis was found to possess an enzyme capable of catalyzing the reaction by which α-hydroxyisovaleric acid is converted to α-ketoisovaleric acid, an intermediate in the valine biosynthetic pathway.

Effects of Heparin Oligosaccharides with High Affinity for Antithrombin III in Experimental Venous Thrombosis

1982 ◽  
Vol 47 (03) ◽  
pp. 244-248 ◽  
Author(s):  
D P Thomas ◽  
Rosemary E Merton ◽  
T W Barrowcliffe ◽  
L Thunberg ◽  
U Lindahl
Keyword(s):  
Antithrombin Iii ◽  
Specific Activity ◽  
High Specific Activity ◽  
Factor Xa ◽  
Blood Levels ◽  
Thrombin Time ◽  
High Affinity ◽  
Very High

SummaryThe in vitro and in vivo characteristics of two oligosaccharide heparin fragments have been compared to those of unfractionated mucosal heparin. A decasaccharide fragment had essentially no activity by APTT or calcium thrombin time assays in vitro, but possessed very high specific activity by anti-Factor Xa assays. When injected into rabbits at doses of up to 80 ¼g/kg, this fragment was relatively ineffective in impairing stasis thrombosis despite producing high blood levels by anti-Xa assays. A 16-18 monosaccharide fragment had even higher specific activity (almost 2000 iu/mg) by chromogenic substrate anti-Xa assay, with minimal activity by APTT. When injected in vivo, this fragment gave low blood levels by APTT, very high anti-Xa levels, and was more effective in preventing thrombosis than the decasaccharide fragment. However, in comparison with unfractionated heparin, the 16-18 monosaccharide fragment was only partially effective in preventing thrombosis, despite producing much higher blood levels by anti-Xa assays.It is concluded that the high-affinity binding of a heparin fragment to antithrombin III does not by itself impair venous thrombogenesis, and that the anti-Factor Xa activity of heparin is only a partial expression of its therapeutic potential.

Autoprothrombin C Activity from Prothrombin with Snake Venom or Trypsin

1962 ◽  
Vol 08 (03) ◽  
pp. 425-433 ◽  
Author(s):  
Ewa Marciniak ◽  
Edmond R Cole ◽  
Walter H Seegers
Keyword(s):  
Snake Venom ◽  
Thrombolytic Agent ◽  
Sodium Citrate ◽  
Specific Activity ◽  
High Specific Activity ◽  
Citrate Solution ◽  
Clotting Factors ◽  
Activation Products ◽  
Russell’S Viper ◽  
Autoprothrombin C

SummarySuitable conditions were found for the generation of autoprothrombin C from purified prothrombin with the use of Russell’s viper venom or trypsin. DEAE chromatographed prothrombin is structurally altered and has never been found to yield autoprothrombin C and also did not yield it when Russell’s viper venom or trypsin were used. Autoprothrombin C is derived from prothrombin with tissue extract thromboplastin, but not in large amounts with the intrinsic clotting factors. With the latter thrombin and autoprothrombin III are the chief activation products. Autoprothrombin III concentrates were prepared from serum and upon activation with 25% sodium citrate solution or with Russell’s viper venom large amounts of autoprothrombin C were obtained, and this was of high specific activity. Theoretically trypsin is not a thrombolytic agent, but on the contrary should lead to intravascular clotting.

THE LESS-POLAR METABOLITES PRODUCED BY INCUBATION OF TESTOSTERONE-4-14C WITH RAT AND BOVINE BRAIN

1969 ◽  
Vol 61 (4) ◽  
pp. 641-648 ◽  
Author(s):  
Leon J. Sholiton ◽  
Emile E. Werk
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Paper Chromatography ◽  
Specific Activity ◽  
Bovine Brain ◽  
Polar Fraction ◽  
End Products ◽  
Polar Metabolites ◽  
Layer Chromatography ◽  
Constant Specific Activity

ABSTRACT Rat and bovine brain have been incubated with testosterone-4-14C under standard conditions. With use of paper chromatography, the extracted metabolites were noted to fall into less-polar, iso-polar, and more polar fractions. The components of the less-polar fraction were separated by acetylation and thin-layer chromatography and the major end-products identified by recrystallization to constant specific activity or constant 3H/14C ratios. Androst-4-enedione and 5α-dihydrotestosterone were formed consistently under the conditions utilized. Trace amounts of other less-polar metabolites were noted occasionally.

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