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381.
382.
383.
The extraction and carrier-facilitated transport of amino acids (leucine, valine and glycine) was studied through chloroform bulk liquid membrane system using a series of non-cyclic receptors such as diethylene glycol (1), diethylene glycol dimethyl ether (2), diethylene glycol dibutyl ether (3), diethylene glycol dibenzoate (4), triethylene glycol (5) and tetraethylene glycol (6). The amount of amino acid extracted and transported depends mainly upon the structure and the concentration of the receptors and also on the concentration of amino acid. The receptors 1 to 4, having small chain length and flexible end groups, formed stable complexes with amino acids, and the flexibility of receptors in different conformational forms was responsible for their carrier ability, while the receptors 5 and 6, having larger chain length showed poor carrier ability. Hydrophobicity of amino acids also play an important role in the extraction as well as transport process. 相似文献
384.
Saran A. Narang 《Journal of biosciences》1984,6(5):739-755
A 355 base pair DNA sequence coding for human preproinsulin has been assembled by joining 55 synthetic deoxyoligonucleotide
fragments prepared by the modified phosphotriester methodology. Proinsulin was expressed underlac promoter control and truncatedΒ-galactosidase 590 amino acid long sequence. The fusedΒ-galactosidase proinsulin protein was produced in amount to 30 % of the totalEscherichia coli proteins. It was also expressed in M13 bacteriophage and yeast system. 相似文献
385.
Pratibha Devarshi Aruna Kanase Ravindra Kanase Sadashiv Mane Subhash Patil A. T. Varute 《Journal of biosciences》1986,10(2):227-234
‘Mandur bhasma’, an ayurvedic preparation of iron is used in traditional medicine against hepatitis. In the present study
the hepatoprotective property of this drug was tested in albino rats during CC14 induced hepatic injury. The effect of mandur bhasma on the activities of the lipolytic enzymes of rat liver, kidney and adipose
tissue were studied during hepatitis induced by CCl4. The activities of acid lipase, alkaline lipase, lipoprotein lipase and hormone sensitive lipase exhibited significant alterations
during CCl4 induced hepatic injury, indicating a role for these enzymes in the mobilization of fat from adipose tissue and accumulation
of fat in liver and kidney. Simultaneous treatment with mandur bhasma prevented the paraffin mediated and CC14 mediated changes in the enzyme activities. These results suggest the hepatoprotective role of mandur bhasma during CCl4 induced hepatic injury. 相似文献
386.
Robert C. A. Yang Michael Dove Verner L. Seligy Claude Lemieux Monique Tunnel Saran A. Narang 《Gene》1986,50(1-3):259-270
387.
Stimulation of an N-ethylmaleimide-sensitive ATPase in the collecting duct segments of the rat nephron by metabolic acidosis 总被引:7,自引:0,他引:7
A plasma membrane ATPase sensitive to inhibition by N-ethylmaleimide (NEM) and insensitive to inhibition by oligomycin and ouabain has been shown to be involved in acidification of urine in the turtle bladder. The activity of this NEM-sensitive ATPase was determined in four types of distal nephron segments of normal rats and in rats treated with ammonium chloride. The enzyme activity was determined by a fluorometric micromethod in which ATP hydrolysis was coupled to NADH oxidation. Significant activities (10-35 pmol ADP X min-1 X mm-1) of NEM-sensitive ATPase were present in the distal convoluted tubule (DCT) and in the cortical and outer and inner medullary collecting duct segments of normal rats. In metabolic acidosis produced by ammonium chloride treatment (plasma CO2 content = 15.3 +/- 0.8 mequiv./L), the NEM-sensitive ATPase activity was increased significantly (60-100%) in the collecting duct segments without showing a significant change in the enzyme activity in the DCT. Our data are consistent with the hypothesis that a plasma membrane H+-ATPase (inhibited by NEM but not by oligomycin or ouabain) is involved in H+ secretion in the mammalian collecting duct. 相似文献
388.
Somatic embryogenesis and regeneration of plants in the bamboo Dendrocalamus strictus 总被引:1,自引:0,他引:1
Somatic embryogenesis leading to plant regeneration has been achieved in the bamboo, Dendrocalamus strictus, by culturing seeds (caryopses) on B5 basal medium supplemented with 2,4-dichlorophenoxyacetic acid. Callus cultures obtained from the embryonal end of the seeds differentiated chlorophyllous embryoids. On transfer to a germination medium (B5 liquid, sucrose, indolebutyric acid, and -naphthaleneacetic acid) 40% of the embryoids developed into plantlets. Further development of the plantlets occured on B5 liquid medium (half strength) + sucrose (1%) + IBA (5 × 10–7M) + NAA (10–7M).Abbreviations 2,4-D
2,4-dichlorophenoxyacetic acid
- IBA
Indolebutyric acid
- NAA
-naphthaleneacetic acid 相似文献
389.
S A Narang J Phipps F L Yao J J Michniewicz G Dubuc R L Somorjai 《Biochemical and biophysical research communications》1987,149(2):340-346
A DNA of 495 bp coding for T4-lysozyme was chemically synthesized and cloned in Escherichia coli. On DNA sequence analysis, clones pTLY.10 and pTLY.9 were identified to contain identical and complete T4-lysozyme coding sequences except that pTLY.9 had an additional 23 bp inverted repeat DNA at the 3'-end of the coding sequence. On expression and purification under similar conditions, T4-lysozymes from these two clones showed different degrees of retention time on HPLC as well as in the rate of enzymatic reaction. We speculate that this difference could be due to the generation of a pause mutant of T4-lysozyme in pTLY.9 under the influence of 3'-inverted repeat DNA that alters the rate of protein synthesis. 相似文献
390.
A 17-nucleotide-long synthetic DNA molecule constituting the minimal recognition sequence of the lactose operator has been cloned in E. coli using the vehicle pBR313 and a synthetic HindIII adaptor. The clones containing the lac-pBR313 hybrid DNA constitutively produced beta-galactosidase. The level of beta-galactosidase was high and comparable to that obtained in cells carrying a 21-nucleotide-long synthetic lac operator on pMB9 plasmid or cells carrying a natural lac operator on pOP203-1 plasmid. 相似文献