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1.
Summary IAA oxixase activity was very high in stem cuttings ofSalix tetrasperma andPopulus robusta, which rooted profusely, less in stem cuttings ofHibiscus rosa sinensis which rooted less, and insignificant in those ofEucalyptus citriodora which did not root at all. Protein(s) extracted from the stem cuttings ofE. citriodora inhibited the activity of IAA oxidase as well as root formation on hypocotyl cuttings ofPhaseolus mungo. The possibility of involvement of IAA oxidase activity in the process of adventitious root formation is discussed.The research has been financed by a grant from U.S. Department of Agriculture.  相似文献   

2.
Summary In the rabbit testicular ornithine decarboxylase activity and androgen content as well as serum androgens were increased 4 h after the injection of HCG. D,L-a-difluoromethylornithine (a-DFMO) alone or together with HCG inhibited enzyme activity although testicular and serum androgens were significantly increased aftera-DFMO and HCG. These data suggest that ODC activity is not required for testicular androgen production.This work was supported by the Medical Research Council of Canada, MT 4192.  相似文献   

3.
Summary 5-Hydroxytryptamine (5-HT) and hypoxanthine were isolated chromatographically from the holothurianPentacter crassa. This study was initiated as a result of the observed hypotensive activity of aP. crassa extract. This activity was also encountered in extracts of the holothuriansThelenota ananus andStichopus chloronatus and can be attributed to 5-HT.  相似文献   

4.
Five novel 1,2-sn-diacylglycerols with diterpenoid acyl moieties in thesn-1 position were isolated and characterized, together with the corresponding 1,3-sn-diacylglycerols, from three species of dorid nudibranchs molluscs. Their potent activity as morphogens in vivo in theHydra tentacle regeneration assay and their parallel activity as activators of rat brain protein kinase C (PKC) in vitro are reported here. Our findings promote the use of these compounds as useful molecular probes for both in vivo and in vitro studies on the participation of PKC in cell development.  相似文献   

5.
Summary The survival time of adultDrosophila melanogaster flies without food is greater in the presence of ethanol, especially for flies of strains or lines with a higher alcohol dehydrogenase activity. It seems that theebony gene can act in some populations as a selective factor favoring the ADHF allele, as well as the minor genes enhancing the alcohol dehydrogenase activity level.Chargé de Recherches au F. N. R. S.  相似文献   

6.
Summary 4-Isothiocyanato-4-nitrodiphenylamine possessed anthelmintic activity againstNippostrongylus dubius andHymenolepis nana in mice andH. diminuta in rats as determined by both egg counts and recovery of parasites at autopsy. No activity was detected against the cestode,Spirometra mansonoides, in cats.This investigation was supported in part by grants AI-10512 and AI-09483 from the National Institutes of Health. The authors are indebted to Dr P.P. Weinstein for providing animals infected withSpirometra mansonoides.  相似文献   

7.
Porphyromonas gingivalis 381 lipopolysaccharide (LPS) definitely exhibited mitogenic activity in purified B-cells, separated from spleens of LPS-responsive C3H/HeN mice and LPS-non-responsive C3H/HeJ mice by using a magnetic cell sorting system. The mitogenic activity induced byP. gingivalis LPS was incompletely inhibited by polymyxin B.P. gingivalis LPS also induced a higher production of interleukin-6 (IL-6) in splenic B-cells of C3H/HeN mice as compared withEscherichia coli LPS. Furthermore,P. gingivalis LPS, but notE. coli LPS, induced definite IL-6 production in C3H/HeJ mice.P. gingivalis LPS increased tyrosine, serine/threonine phosphorylation of proteins with various major induced bands in splenic B-cells of both C3H/HeN and C3H/HeJ mice. Additionally, radioiodinatedP. gingivalis LPS, similarly toE. coli LPS, bound to a 73-kDa protein on C3H/HeJ as well as C3H/HeN B-cells. ThusP. gingivalis LPS may activate B-cells of C3H/HeJ as well as C3H/HeN mice via the LPS-specific binding protein on the cells.  相似文献   

8.
Summary A regulatory element tightly linked to theGpdh locus inDrosophila melanogaster has been isolated from a natural population. Flies homozygous for second chromosomes bearing the element,H31, have half the GPDH activity of normal homozygotes. Heterozygotes betweenH31 andF orS alleles exhibit dominance in GPDH activity. Heterozygotes betweenH31, F orS andDf(2L) GdhA have half the diploid level. The contribution of theS allele to the activity inS/H31 heterozygotes is more than four times that ofH31. The regulatory element distinguishingH31 is tightly linked to theGpdh + locus.  相似文献   

9.
10.
Protein phosphorylation is a well-characterized biochemical process for reversible regulation of protein activity. Protein kinases and protein phosphatases are the key complementary players in this process, and through their coordinated activity cell homeostasis is tightly controlled. If these enzymes display aberrant activity, cells may undergo unrestrained growth, thus giving rise to complex diseases such as cancer. The technological platform gathered during the Human Genome Project recently allowed the systematic identifi cation of the genetic alterations present in the kinase (the kinome) and the phosphatase (the phosphatome) gene families. These studies suggest that most if not all human tumors carry genetic alterations in at least one phosphatase or kinase gene. Here we integrate the biochemical knowledge on the properties of these molecules with the information collected through their systematic genetic analysis in cancer. We also analyze why the molecular profi ling of the kinome and phosphatome in individual cancers is revolutionizing basic and clinical oncology.Received 13 May 2005; received after revision 30 May 2005; accepted 22 June 2005  相似文献   

11.
Summary Sex-converted males and females of Xenopus were raised to sexual maturity. Cross-breeding proves that the entire differentiation and reproductive function of females can occur in animals of the genetic constitutionZZ andWW as well as the normalZW. Moreover, functional males have been obtained with theZW as well as theZZ constitution. Experiments with the aim of producing alsoWW males are in progress. It is concluded that the sex genes and chromosomes which in normal reproduction decide male or female direction of differentiation are restricted in their activity, to the very first steps of normal sex development.

Arbeiten unterstützt durch Grant No. G-14057 der National Science Foundation und Grant No. C-3993 des National Institute of Health (USPHS).  相似文献   

12.
Genome clones and expressed sequence tags (ESTs) from the ascidian Ciona intestinalis and from the larvacean Oikopleura dioica were analysed for the presence of lysozyme-encoding genes. Two genes were found to potentially code for goose-type lysozymes in Oikopleura, while three or possibly more g-type proteins form the lysozyme complement of C. intestinalis, and at least one of these genes from each species is expressed based on EST data. No genes for chicken- or invertebrate-type lysozymes were found in either urochordate species. Consistent with this finding, extracts of Oikopleura animals possessed hydrolysing activity on bacterial cell walls, and this activity was not inhibited in the presence of a known inhibitor of chicken-type lysozyme. A wide range of isoelectric points for the predicted lysozymes from Ciona (pI 4.4, 6.4 and 9.9) and from Oikopleura (pI 5.0 and 8.0) suggests tissue-specific adaptations as well as specific functional roles of the lysozymes. Comparisons of gene structures, encoded sequences, cysteine residue content and their positions in the proteins indicate that the g-type lysozymes of Ciona intestinalis are more closely related to those of vertebrates than are the g-type lysozymes of Oikopleura. Multiple genes from each species may result from separate and lineage-specific duplications followed by functional specialisation.Received 29 June 2003; received after revision 24 July 2003; accepted 29 July 2003  相似文献   

13.
Summary (1) In homozygous state, the geneebony noticeably diminishes the sexual activity of the males.(2) The lower activity on the part of the malese is responsible for the non-random breeding in the cross betweene and +.(3) The degree of sexual isolation which results from this, depends not only on the genic, but also on the cytoplasmic context which accompanies theebony gene.(4) Results of previous experiments seem to indicate that in heterozygous state, theebony mutation increases instead of diminishing the activity.(5) Attention is drawn to the selective importance of these differences and the role they can play in artificial populations whereebony is made to compete with its normal allel.  相似文献   

14.
Digestive enzymes of some earthworms   总被引:3,自引:0,他引:3  
Summary 4 species of tropical earthworms differed with regard to enzyme activity. The maximum activity of protease and of cellulase occurred in the posterior region of the gut of the earthworms. On the averageOctochaetona surensis shows maximum activity andDrawida calebi shows minimum activity for all the enzymes studied.  相似文献   

15.
Summary Several quassinoids, obtained by isolation and derivatization fromSimaba multiflora andSoulamea soulameoides, were evaluated for growth inhibitory and insecticidal effects against the tobacco budworm (Heliothis virescens) and for antifeedant effects againstH. virescens and the fall armyworm (Spodoptera frugiperda). The relative activity of the quassinoids as insect growth inhibitors generally paralleled their known relative potency as antileukemic and cytotoxic agents.Phytochemical aspects of this work were supported by Contract CM-97295 with the Division of Cancer Treatment, National Cancer Institute, National Institutes of Health, Bethesda, Md. Insects were kindly supplied by the agency of the United States Department of Agriculture at Brownsville, TX.  相似文献   

16.
Summary Rhizoctonia bataticola is responsible for the spoilage of mango fruits (Mangifera india) during post-harvest preservation and storage. Culture ofR. bataticola exhibited significant pectinase and cellulase activity. InRhizoctonia-infected fruits an increase of protease and cellulase activity, and a decrease in certain enzymes of carbohydrate metabolism, were observed in comparison to healthy fruits.  相似文献   

17.
Summary By means of a technic published in this journal (2, 66 [1946]), it has been observed that the activity of the pseudo-choline esterase of the serum is highest in presence of high concentrations of acetylcholine.The true choline esterase of the red corpuscules has her optimal activity at concentrations of 200 mg % acetylcholine. This high activity of these choline esterase is only going on during 3 to 5 minutes; after this period an inhibition occurs. At lower substrate concentrations (50 mg % acetylcholine) the difference in activity in the first and second phase is becoming less pronounced and the curve of the choline esterase activity becomes a straight line. At the small substrate concentration (4 mg % acetylcholine) again a primary higher choline esterase activity has been observed.Choline inhibitsin vitro the activity of the choline esterase. Prostigmine inhibits alsoin vivo andin vitro, the choline esterase of serum and globules.  相似文献   

18.
Biochemistry of frog ribonucleases   总被引:10,自引:0,他引:10  
Frogs have unique pyrimidine base-specific RNases, with structures similar to those of turtle, iguana and chicken RNases. Among the four frog RNases discussed here, three from Rana pipiens, R. catesbeiana and R. japonica oocyte cells show anti-tumour activity, and the latter two show lectin activity towards sialic acid-rich glycoproteins. In this review, (i) we compare their unique primary structures with respect to the locations of their disulphide bridges, three-dimensional structure, base specificity and heat stability as compared with RNase A, and (ii) we summarize current knowledge about the mode of action of lectin and the antitumour activities of the three frog RNases.  相似文献   

19.
Summary Methallibure treatment is as effective as hypophysectomy in reducing thyroid activity inH. fossilis. Sex steroids (TP and EB) administration restored thyroid activity in methallibure-treated females to normal level, but failed to elicit any response in males. This drug seems to block TSH secretion and thyroid hormone synthesis inH. fossilis.Financial assistance in the form of SRF from ICAR, New Delhi to one of us (R.B.R.), gift of methallibure from ICI Ltd., UK and TSH from NIH, USA, to T.P.S. are gratefully acknowledged.  相似文献   

20.
Alcohol dehydrogenase 3 (ADH3) has been assigned a role in nitric oxide homeostasis due to its function as an S-nitrosoglutathione reductase. As altered S-nitrosoglutathione levels are often associated with disease, compounds that modulate ADH3 activity might be of therapeutic interest. We performed a virtual screening with molecular dockings of more than 40,000 compounds into the active site of human ADH3. A novel knowledge-based scoring method was used to rank compounds, and several compounds that were not known to interact with ADH3 were tested in vitro. Two of these showed substrate activity (9-decen-1-ol and dodecyltetraglycol), where calculated binding scoring energies correlated well with the logarithm of the k cat/K m values for the substrates. Two compounds showed inhibition capacity (deoxycholic acid and doxorubicin), and with these data three different lines for specific inhibitors for ADH3 are suggested: fatty acids, glutathione analogs, and cholic acids.  相似文献   

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