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Kuriyama R, Dasgupta S, Borisy GG. Independence of centriole formation and initiation of DNA synthesis in Chinese hamster ovary cells. CELL MOTILITY AND THE CYTOSKELETON 1986; 6:355-62. [PMID: 2875802 DOI: 10.1002/cm.970060402] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The relationship between centriole formation and DNA synthesis was investigated by examining the effect of taxol on the centriole cycle and the initiation of DNA synthesis in synchronized cells. The centriole cycle was monitored by electron microscopy of whole-mount preparations [Kuriyama and Borisy, J. Cell Biol., 1981, 91:814-821]. A short daughter centriole appeared in perpendicular orientation to each parent during late G1 or early S and elongated slowly during S to G2. Addition of 5-20 micrograms/ml taxol to a synchronous population of cells in S phase did not inhibit centriole elongation; rather, elongation was accelerated. In contrast, when taxol was added to M phase or early G1 cells, centriole duplication was completely inhibited. The taxol block was reversible since nucleation and elongation of centrioles resumed as soon as the drug was removed. Cells exposed to taxol progressed through the cell cycle and became blocked in mitosis, as indicated by an increase in the mitotic index, but eventually the mitotic arrest was overcome, resulting in formation of multinucleated cells. A peak in mitotic index was seen in the following generation, indicating that chromosomes duplicated in the presence of taxol. Incorporation of 3H-thymidine followed by autoradiography confirmed that DNA synthesis was initiated in the presence of taxol even though formation of daughter centrioles was inhibited. It seems, therefore, that centriole duplication is not a prerequisite for entry into S phase. Since DNA synthesis has already been demonstrated not to be necessary for centriole duplication, these two events, normally coordinated in time, appear to be independent of each other.
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327
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Dasgupta S, Spiro TG, Johnson CK, Dalickas GA, Hochstrasser RM. Picosecond resonance Raman evidence for unrelaxed heme in the (carbonmonoxy)myoglobin photoproduct. Biochemistry 1985; 24:5295-7. [PMID: 4074696 DOI: 10.1021/bi00341a003] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
An actively and passively mode-locked Nd:YAG laser, producing 30-ps pulses of 1-mJ energy at 532 nm, has been used to photolyze (carbonmonoxy)myoglobin (MbCO) and generate its resonance Raman spectrum, which was recorded with a vidicon multichannel analyzer. The photoproduct spectrum was obtained by subtraction of the MbCO spectrum, obtained at lower incident power levels. Comparison with the spectrum of deoxyMb, obtained with the same apparatus, revealed frequency downshifts of approximately 4 cm-1, for bands at 1604, 1554, and 1542 cm-1, which are identified with porphyrin skeletal modes v10, v19, and v11. These frequencies are known to correlate inversely with the core size of the porphyrin ring, and the shifts imply a larger core size for the photoproduct than for deoxyMb. Similar shifts have been observed for the (carbonmonoxy)hemoglobin (HbCO) photoproduct; in that case, the shifts persist for longer than 20 ns, whereas they are absent in the MbCO photoproduct spectrum within 7 ns of photolysis. The unrelaxed state of the heme group region is therefore suggested to be maintained by protein forces, which relax more rapidly for Mb than Hb. This may reflect a tighter coupling in Hb of the out-of-plane movement of the Fe atom with the proximal histidine-containing F helix.
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328
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Dasgupta S, Sengupta S. Homogeneous deformation theory for piezoelectric crystals using the Ewald transformation and relationships among electrostatic contributions to second- and third-order elastic constants. PHYSICAL REVIEW. B, CONDENSED MATTER 1985; 31:8275-8279. [PMID: 9935787 DOI: 10.1103/physrevb.31.8275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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329
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Dasgupta S, Pluskal MG, Sarkar S. The cytoplasmic 4S translation inhibitory RNA species of chick embryonic muscle: fractionation of biologically active subspecies by high performance liquid chromatography. PREPARATIVE BIOCHEMISTRY 1984; 14:331-47. [PMID: 6083558 DOI: 10.1080/10826068408070639] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
A 4S RNA species (iRNA) isolated from chick embryonic muscle which is a potent inhibitor of mRNA translation in vitro shows heterogeneity in the 70-100 nucleotide size range (Sarkar, S., Mukherjee, A.K., and Guha, C. (1981) J. Biol. Chem., 256, 5077-5086). The iRNA was fractionated by HPLC on different size exclusion columns using a variety of elution conditions. Chromatography of iRNA on a TSK 4000 SW column and elution with a low ionic strength buffer gave three components, one of which contained a pure subspecies of about 90-100 nucleotides size, as shown by a single band on PAGE analysis in 99% formamide. The biological activity of this purified subspecies showed that this is a more potent inhibitor of globin mRNA translation than unfractionated iRNA (Sarkar, S., Mukherjee, A.K., and Guha, C., (1981) J. Biol. Chem. 256, 5077-5086). Partial resolution of three additional low molecular weight iRNA subspecies in the 70-80 nucleotide size range in biologically active form was obtained on chromatography of unfractionated iRNA on TSK 4000 SW column in the presence of 0.5 M NaCl or on TSK 3000 SW column in the presence of low salt. The fractionation of iRNA by HPLC appears to be primarily based on size. These results strongly suggest that HPLC may also be useful for the fractionation of a variety of low molecular weight eukaryotic nuclear and cytoplasmic RNAs with retention of biological activity.
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330
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Paul AK, Mandal U, Dasgupta S. Oral paediatric premedication. JOURNAL OF THE INDIAN MEDICAL ASSOCIATION 1984; 82:233-5. [PMID: 6545898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/05/2023]
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331
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Leskawa KC, Dasgupta S, Chien JL, Hogan EL. A simplified procedure for the preparation of tritiated GM1 ganglioside and other glycosphingolipids. Anal Biochem 1984; 140:172-7. [PMID: 6486403 DOI: 10.1016/0003-2697(84)90149-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The ganglioside II3NeuAc-GgOse4Cer and other glycosphingolipids can be radiolabeled to high specific activity by the galactose oxidase-NaB3H4 procedure, by purifying the oxidized compounds prior to reductive labeling. The oxidized products are separated from nonoxidized compounds and detergents (Triton X-100 and sodium taurocholate) present during the enzymatic oxidation. Since the oxidized derivatives are separated, the final specific activity depends solely upon the specific activity of the NaB3H4 and the reduction conditions.
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332
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El-Kawi MA, Slatkin DJ, Schiff PL, Dasgupta S, Chattopadhyay SK, Ray AB. Additional alkaloids of Pachygone ovata. JOURNAL OF NATURAL PRODUCTS 1984; 47:459-464. [PMID: 6481360 DOI: 10.1021/np50033a010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Pachygone ovata (Menispermaceae), indigenous to the sandy seashores of southern India, is a woody climber whose fruits have been used as a rodenticide and fish poison. Chromatography of the extract of the roots resulted in the reisolation of the alkaloids liriodenine, coclaurine, trilobine (1), and magnoflorine and the isolation of stepholidine, coreximine, isoboldine, norjuziphine, and nortrilobine (2). Nortrilobine (2) is a new dibenzo-p-dioxin bisbenzylisoquinoline alkaloid whose structure was established by a consideration of spectral data and conversion to isotrilobine (3).
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333
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Hogan EL, Chien JL, Dasgupta S. Glycosphingolipids of chicken skeletal muscle in early development and genetic dystrophy. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1984; 174:287-96. [PMID: 6741734 DOI: 10.1007/978-1-4684-1200-0_24] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The acidic and neutral GSL of chicken pectoral muscle and the activities of relevant sialyltransferase and glycosidases have been examined during embryonic and early post-hatching development. At this stage of myogenesis, a prominent shift to the neutral GSL of longer oligosaccharide length involving Forssman glycolipid most prominently and also globoside and GbOse3Cer occurred but the distribution of muscle-type gangliosides was not obviously affected. The glycosidase and sialyltransferase activities decreased dramatically just prior to or at hatching. The fusion-linked change in GSL suggests a role for terminal galactosamine and/or galactose residues in myoblast aggregation. A parallel developmental study of genetic muscular dystrophy revealed similar GSL levels and enzyme activities. A larger proportion of lactosylceramide in dystrophic muscle throughout development suggests a developmental lag in the mutant.
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334
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Valenzuela MS, Mueller GC, Dasgupta S. Nuclear matrix-DNA complex resulting from EcoR1 digestion of HeLa nucleoids is enriched for DNA replicating forks. Nucleic Acids Res 1983; 11:2155-64. [PMID: 6300795 PMCID: PMC325868 DOI: 10.1093/nar/11.7.2155] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Upon treatment of HeLa nucleoids with EcoR1 restriction enzyme, a minute fraction of the DNA remains attached to the nuclear matrix. This matrix-DNA complex appears to be composed of a unique set of proteins. Electron microscopic analysis of the DNA fragments present shows an enrichment for HeLa DNA replicating forks.Images
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335
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Chattopadhyay PK, Dasgupta S, Laha H. Physiological and psychological aspects of anxiety in psychiatric patients and normal subjects. Indian J Psychiatry 1982; 24:159-63. [PMID: 21965905 PMCID: PMC3012866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Physiological (Skin conductance) and Psychological (State-trait anxiety) measures of anxiety were employed to assess the level of anxiety in 10 anxious neurotics, 10 schizophrenics and 10 normal subjects. Both the Physiological and Psychological measures were sensitive in detecting the level of anxiety in normals and patients. But interrelationships between these two measures were very poor.
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336
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Sarkar P, Dasgupta S. Complications of intramuscular injections in children. JOURNAL OF THE INDIAN MEDICAL ASSOCIATION 1981; 77:145-7. [PMID: 7341686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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337
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Lilaram D, Basu S, Khan PK, Dey A, Dasgupta S. Evaluation of 496 menstrual regulation and abortion patients in Calcutta. Int J Gynaecol Obstet 1978; 15:503-6. [PMID: 29797 DOI: 10.1002/j.1879-3479.1977.tb00743.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
From March to December 1975, 496 patients were studied to compare the safety and effectiveness of menstrual regulation (MR) performed with a Karman hand syringe and first trimester abortion performed with an electric vacuum aspirator. All procedures were done on an outpatient basis. The complication rate for the MR patients was significantly lower than that for the other first trimester abortion patients. Study results indicate that MR with the Karman syringe is a safer, simpler and less costly procedure than first trimester abortion with the electric vacuum aspirator. Further research and study are necessary to determine the effect of the initial and repeat MR procedures on women's menstrual patterns and future pregnancies, including any subsequent prematurity, stillbirths and Rh immunization.
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338
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Sinha BC, Dasgupta S. Masking of manganese in relation to stepwise complexometric determination of calcium, magnesium and manganese. Talanta 1978; 25:693-5. [PMID: 18962349 DOI: 10.1016/0039-9140(78)80174-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/1977] [Revised: 04/17/1978] [Accepted: 06/02/1978] [Indexed: 10/18/2022]
Abstract
A critical study has been made of the masking of manganese with potassium cyanide in alkaline medium for complexometric titration of calcium and magnesium. It has been found that there is incomplete oxidation to manganese(III) unless the solution is aged for a sufficient period or air is bubbled through the solution at 35 +/- 5 degrees for 10 min. The manganese(III) complex can be reduced with ascorbic acid for titration with EDTA. Procedures are given for stepwise titration of magnesium, manganese and calcium in silicate materials. Mixed indicators are used, to improve the end-points.
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339
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Dasgupta S. Polypropylene filled with barium titanate: Dielectric and mechanical properties. J Appl Polym Sci 1978. [DOI: 10.1002/app.1978.070220827] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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340
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Dasgupta S, Dasgupta B, Chatterjee A, De NC, Nandi J, Saha K, Roy R, Ghosh M, Majumdar G. Dipetalonema laemmleri sp. nov. (Nematoda: Dipetalonematidae) from the Himalayan flying squirrel, Petaurista magnificus. ZEITSCHRIFT FUR PARASITENKUNDE (BERLIN, GERMANY) 1978; 55:195-8. [PMID: 567902 DOI: 10.1007/bf00390370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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341
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Dasgupta S, Mitra S. Structure of nascent replicative form DNA of coliphage M13. Proc Natl Acad Sci U S A 1978; 75:153-7. [PMID: 272630 PMCID: PMC411203 DOI: 10.1073/pnas.75.1.153] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Nascent replicative form type II (RFII) DNA of coliphage M13 synthesized in an Escherichia coli mutant deficient in the 5' leads to 3' exonuclease associated uith DNA polymerase I contains ribonucleotides that are retained in the covalently closed RFI DNA sealed in vitro by the joint action of T5 phage DNA polymerase and T4 phage DNA ligase. These RFI molecules are labile to alkali and RNase H, unlike the RFI produced either in vivo or from RFII with E. coli DNA polymerase I and E. coli DNA ligase. The ribonucleotides are located at one site and predominantly in one strand of the nascent RF DNA. Furthermore, these molecules contain multiple small gaps, randomly located, and one large gap in the intracistronic region.
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342
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Dasgupta S, Mitra S. The role of DNA polymerase I-associated 5'-exonuclease in replication of coliphage M13 replicative-form DNA. Biochem Biophys Res Commun 1977; 78:1108-13. [PMID: 334178 DOI: 10.1016/0006-291x(77)90535-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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343
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Dasgupta S, Allison DP, Snyder CE, Mitra S. Base-unpaired regions in supercoiled replicative form DNA of coliphage M13. J Biol Chem 1977; 252:5916-23. [PMID: 328505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Superhelical covalently closed circular replicative form DNA (RF I) of coliphage M13 appears as a relaxed molecule that has a base-unpaired region in the form of a bubble (100 to 200 base pairs long) seen in electron micrographs when spread in the presence of formaldehyde and formamide or after pretreatment with glyoxal. S1 endonuclease, specific for single-stranded DNA, converts superhelical M13 RF I DNA, but not nonsuperhelical M13 RF I to a significant extent, into unit-length linear molecules by sequential nicking of two strands. The locations of S1 nuclease-susceptible sites and glyoxal-fixed base-unpaired regions were both related to the five A-T-rich regions in M13 RF DNA. While S1 nuclease does not show preference for any of these sites, glyoxal-fixed bubbles occur predominantly at the major A-T-rich region in M13 RF DNA.
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344
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Dasgupta S, Mitra S. The role of Escherichia coli dnaG function in coliphage M13 DNA synthesis. EUROPEAN JOURNAL OF BIOCHEMISTRY 1976; 67:47-51. [PMID: 786625 DOI: 10.1111/j.1432-1033.1976.tb10630.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Examination of the role of Escherichia coli dnaG function in different stages of M13 phage DNA synthesis by ultracentrifugal analysis of intracellular phage DNA in a thermosensitive dnaG mutant shows that: (a) the formation of parental double-strand replicative-form DNA (rfDNA) from the infecting virus is independent of dnaG function; (b) the synthesis of progeny rfDNA requires dnaG product; (c) after a pool of rfDNA is made up, dnaG function is not required for the progeny single-strand DNA (ssDNA) synthesis. The ssDNAs produced under nonpermissive condition are mostly circular and biologically functional.
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345
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Das GC, Dasgupta S, Das Gupta NN. Interaction of nogalamycin with DNA. BIOCHIMICA ET BIOPHYSICA ACTA 1974; 353:274-82. [PMID: 4852504 DOI: 10.1016/0005-2787(74)90020-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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346
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Dasgupta S, Ghosh BN. Structure of glycolipid from goat erythrocytes. INDIAN JOURNAL OF BIOCHEMISTRY & BIOPHYSICS 1974; 11:172-4. [PMID: 4448471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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347
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Dasgupta S, Ghosh BN. Chemical and immunological nature of Forssman hapten in sheep erythrocytes. INDIAN JOURNAL OF BIOCHEMISTRY & BIOPHYSICS 1974; 11:36-9. [PMID: 4474139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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348
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Dasgupta S, Misra DN. Conformation of proflavine-bound DNA molecules. ZEITSCHRIFT FUR NATURFORSCHUNG. SECTION C, BIOSCIENCES 1974; 29:128-9. [PMID: 4276689 DOI: 10.1515/znc-1974-3-404] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Abstract
Proflavine, DNA, Electron Microscopic Study The conformational changes suffered by full-length double-stranded DNA molecules from bac teriophage T7, due to their binding with the mutagenic dye proflavine (PF), has been studied by electron microscopy. The dye-bound DNA showed a smoother contour and a more compact con figuration in comparison with the dye-free native DNA. These changes resulted from the stretching, extension and charge-neutralization accompanying the incorporation of PF.
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349
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Dasgupta S, Smyth CP. Influence of intramolecularly compensated dipoles upon collision absorption in liquids. J Chem Phys 1974. [DOI: 10.1063/1.1681269] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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350
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Matsumoto LH, Dasgupta S. Cytoplasmic alteration of an established pattern of Rana pipiens chromosomal DNA replication. Dev Biol 1974; 37:28-34. [PMID: 4545073 DOI: 10.1016/0012-1606(74)90166-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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