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1.
G. -J. A. Vidugiris A. V. Gudavičius V. J. Razumas J. J. Kulys 《European biophysics journal : EBJ》1989,17(1):19-23
Surface enhanced Raman scattering (SERS) of some enzymes (alkaline phosphatase, horseradish peroxidase and lactoperoxidase) and some amino acids (tryptophan, tyrosine and phenylalanine) on silver electrodes has been studied. The spectral band intensities of certain amino acids and amino acid residues were determined by their orientation on the surface and depended on the electrode potential (E).Abbreviations SERS
surface enhanced Raman scattering
- Trp
tryptophan
- Tyr
tyrosine
- Phe
phenylalanine
- E
electrode potential
- ORC
oxidation-reduction cycle 相似文献
2.
Histochemical studies on localisation of lipids, lipase and phosphomonoeste-rases in the crown skin of male baya during non-breeding
and breeding seasons were carried out. The results indicated a high turnover rate for lipid synthesis and its utilisation,
increased acid and alkaline phosphatase activities in the crown skin of breeding male baya as compared to that in non-breeding
season. It is surmised that crown skin of male baya becomes metabolically hyperactive during breeding season aiding processes
such as cell growth and proliferation, keratinization and production of coloured feathers related to breeding. 相似文献
3.
Hemolymph glucose, alkaline phosphatase, lactic dehydrogenase, and creatine phosphokinase in Biomphalaria glabrata infected with Angiostrongylus costaricensis were significantly higher on day 27 postinfection (PI) than in uninfected snails. Hemolymph total calcium from infected snails was less on days 6, 12, and 27 PI than that from controls. Total hemolymph protein was similar for controls and infected animals during the entire study. Throughout the study the mean number of amoebocytes/mm3 hemolymph from infected snails was significantly less than that for controls. Mean total wet weights of digestive gland and foot muscle from infected and uninfected snails was similar throughout the study. Mean μg glycogen/mg wet weight of digestive gland from infected snails was significantly greater on days 24, 27, and 28 PI than that from controls. Mean μg glycogen/mg wet weight of foot muscle from infected snails was significantly reduced between days 12 and 28 PI from that of uninfected snails. It is suggested that hemolymph glucose and digestive gland glycogen in infected snails are augmented by glycogen breakdown in the foot muscle of parasitized animals. Elevations in hemolymph enzymes are due to tissue destruction by larvae emerging from the foot muscle of infected snails. Parasite-induced derangements in shell metabolism underlie observed changes in hemolymph calcium in infected snails. 相似文献
4.
A. Shteyer D. Gazit I. Binderman I. A. Bab 《In vitro cellular & developmental biology. Plant》1987,23(1):15-20
Summary Cells of the dental papilla are capable of odontoblastic, fibroblastic, and endothelial differentiation and formation of dentin
and the dental pulp. In the present study dental papilla cells, obtained from human tooth buds (HDP cells), were cultured
in vitro through 3 to 7 passages. After exposure to prostaglandin E2 there was a marked decrease in intracellular cyclic AMP (cAMP) levels as compared to hormone-free controls. Parathyroid hormone
and calcitonin had stimulatory effects with 1 and 2 log increases in cAMP, respectively. The HDP cells showed moderate activity
of alkaline phosphatase, 1 log higher than that of hamster kidney fibroblasts (BHK 13) and 1 log lower than that of osteoblastic
osteosarcoma cells (ROS 17/2). When cultured for 4 or 8 wk in diffusion chambers (DC) implanted in athymic mice, many of the
HDP cells underwent odontoblastic morphodifferentiation with very long, single processes extending into the matrix. This matrix
contained banded and unbanded collagen fibers. Neither light nor electron microscopy of the DC content revealed mineral deposits.
These results suggest that HDP cells have an intrinsic potential for partial odontoblastic differentiation; inductive signals
like those originating from odontogenic epithelium are probably essential for the completion of hard tissue formation. 相似文献
5.
Psychoactive drugs like chlorpromazine (CPZ), imipramine, lithium and amphetamine in one way or another affect behaviour. The drug responses are presumably mediated by inducing a change in the activity of membrane bound enzymes. CPZ is very potent in inhibiting the alkaline phosphatase activity in rat brain. The combined effect of CPZ with other drugs shows that CPZ and imipramine together inhibit the enzyme activity significantly greater than the individual inhibition either by CPZ or by imipramine alone. Effective inhibition of the alkaline phosphatase activity with a single drug or combined drugs may lead to a change in neuronal permeability through glucocorticoids thereby affecting mood. 相似文献
6.
A thermophilic Bacillus stearothermophilus strain AP-4 excreting a thermostable alkaline protease, was isolated from a local compost. Maximum activity of protease (250 U/ml) was after 36 h growth in broth at pH 9.0 and at 55°C. The protease was optimally active at pH 9.0 and 55°C and was stable in 5 mm CaCl2. The enzyme was completely inactivated by PMSF, EDTA and -mercaptoethanol. It is therefore a metal ion-dependent, alkaline, serine protease.R. Dhandapani and R. Vijayaragavan are with the Centre for Plant Molecular Biology & Biotechnology, Tamil Nadu Agricultural University, Coimbatore 641 003, India 相似文献
7.
8.
Catherine Jumarie Christiane Malo 《In vitro cellular & developmental biology. Animal》1994,30(11):753-760
Summary Caco-2 cell human colon adenocarcinoma cell line was used to study the hormonal regulation of small intestinal epithelial
cell differentiation. We had previously shown that insulin-transferrin-selenium and triiodothyronine (5 × 10−8
M)-supplemented medium can best replace serum after 2 days of culture for both the maintenance and differentiation of Caco-2
cells. The present study demonstrates that precoating petri dishes with complete serum allows the growth and differentiation
of Caco-2 cells seeded directly in serum-free medium. On the other hand, precoating with dialyzed serum inhibits alkaline
phosphatase and dipeptidyl-dipeptidase IV activities by more than 50%. The results obtained with complete serum-precoated
culture plates indicate that there is no synergy between insulin and triiodothyronine because cells maintained in transferrin-selenium
and triiodothyronine-supplemented medium, with or without insulin, express comparable enzyme activities. Moreover, large increases
in alkaline phosphatase and dipeptidyl-dipeptidase IV activities were observed when triiodothyronine was added to the culture
medium by the time confluency was reached. In contrast, γ-glutamyltransferase was lowered to a greater extent when triiodothyronine
was present from the beginning of culture. These findings show that triiodothyronine preferentially stimulates alkaline phosphatase
and dipeptidyl-dipeptidase IV activities during the differentiation period whereas it selectively inhibits γ-glutamyltransferase
during the proliferation phase. Triiodothyronine acts in a dose-dependent manner. 相似文献
9.
Nobuko Naito Evelyn Grace De Jesus Yasumitsu Nakai Tetsuya Hirano 《Cell and tissue research》1993,272(3):429-437
Tissue non-specific alkaline phosphatase is a membrane-bound glycoprotein enzyme which is characterized by its phosphohydrolytic, protein phosphatase, and phosphotransferase activities. This enzyme is distributed virtually in all mammalian tissues, particularly during embryonic development. Its expression is stagespecific and can be demonstrated in the developing embryo as early as the 2-cell stage. It has been suggested that tissue non-specific alkaline phosphatase might play a role in tissue formation. In the study reported here, a genetransfer approach was employed to investigate possible roles for this enzyme by inserting the cDNA for rat tissue non-specific alkaline phosphatase into CHO and LLC-PK1 cells. Permanently transfected cell-lines expressing varying levels of alkaline phosphatase were estblished. The data showed that functional enzyme was expressed in the transfected cells. Cell spreading and attachment were enhanced in transfected CHO cells expressing high levels of tissue non-specific alkaline phosphatase but not in the LLC-PK1 cells. Further, in CHO cells, proliferation was shown to be inversely proportional to the level of the tissue non-specific alkaline phosphatase expression. Homotypic cell association was demonstrated in both alkaline phosphatase-positive and alkaline phosphatase-negative cells in both CHO and LLC-PK1 celllines. Taken together, these findings suggest that in addition to a role in mineralization of bone, tissue nonspecific alkaline phosphatase might also play a role in other cell activities, including those related to differentiation, such as cell-cell or cell-substrate interaction and proliferation. 相似文献
10.
Alkaline borohydride treatment is widely used for the release of carbohydrate moieties from O-glycosylated glycoproteins and mucins. We have adapted this procedure to micro quantities of glycoproteins blotted on membranes. After electrophoresis and transfer to nitrocellulose, nylon or polyvinylidene difluoride membrane, alkaline borohydride treatment was done directly on glycoprotein containing areas of membrane which were cut out with the aid of guide strips stained with Coomassie Blue or lectin-digoxigenin. In combination with standard saccharide fractionation techniques, this procedure can be used to characterize the oligosaccharides of mucins or mucin-type glycoproteins that are separated by gel electrophoresis from crude sources. Using this approach we have characterized the saccharides derived from the two species of epitectin, a malignancy-associated mucin type glycoprotein, isolated from metabolically labelled H.Ep2 cells. 相似文献