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11.
M P Kirpichnikov A V Kurochkin B K Chernov F Buck K D Hahn 《Molekuliarnaia biologiia》1986,20(6):1562-1569
An oligodeoxyribonucleotide composed of 17 residues, d(TATCACCGCCAGAGGTA), and a complementary chain were synthesized. Their duplex was identical with the operator OR1, the binding site for bacteriophage lambda cro and c1 repressors. The 1H NMR spectra (500 MHz) of the duplex imino and aromatic protons were studied at 10, 20 and 25 degrees C. Signals from the imino protons of complementary base pairs and from the C2 protons of adenine (with the exception of the duplex terminal nucleotides) were assigned using the NOE technique and the known characteristics of short DNA fragment melting. No signals from the imino protons of the terminal base pairs were detected even at 10 degrees C due to fraying which increased as the temperature was raised. The assignment of signals can be used to identify centers of interaction between the operator OR1 and repressors, as well as to study possible local changes in DNA geometry. 相似文献
12.
More than 3000 spontaneous and induced lys2 mutants were obtained in haploid and diploid strains of yeast Saccharomyces. The ability to utilize alpha-aminoadipate was used for lys2 mutant screening. The spontaneous and induced mutation rates were measured in haploid and diploid strains. Mitotic segregation of pho1 marker linked to LYS2 was studied in lys2 mutants obtained in diploid strains. Fertility of diploid lys2 mutants was tested. The conclusion to be drawn from the data presented is that mutations appeared in one of two homologous chromosomes and then segregated by mitotic homozygotization. 相似文献
13.
K. D. Hahn F. Buck H. Rüterjans B. K. Chernov K. G. Skryabin M. P. Kirpichnikov 《European biophysics journal : EBJ》1985,12(2):87-95
The 17 base pair operator O
R
3 oligonucleotide, which is the preferential binding site for the Cro repressor of phage , was studied by two-dimensional NMR spectroscopy. A sequential assignment procedure based on two-dimensional Nuclear Overhauser Effect (NOESY) and scalar coupling correlated (COSY) NMR spectroscopy, together with the knowledge of the oligodesoxynucleotide sequence, made it possible to assign the non-exhangeable base protons and the H1 and the H2-H2 sugar protons of the O
R
3 operator DNA. The pattern of the observed NOE connectivities is consistent with a right-handed helical DNA structure. The base and sugar proton assignments provide the necessary information for further studies of the O
R
3 operator — Cro repressor interaction.Abbreviations COSY
correlated spectroscopy
- FID
free induction decay
- NOE
nuclear Overhauser effect
- NOESY
nuclear Overhauser effect spectroscopy
- RD
relaxation delay
- TSP
sodium 3-trimethylsilyl-(2,2,3,3-2H4)propionate
- EDTA
sodium ethylendiamine tetraacetate 相似文献
14.
15.
The absence of non-local conformational changes in OR3 operator DNA on complexing with the cro repressor 总被引:4,自引:0,他引:4
M P Kirpichnikov A P Yartzev L E Minchenkova B K Chernov V I Ivanov 《Journal of biomolecular structure & dynamics》1985,3(3):529-536
The Interaction of the cro protein of lambda phage with a synthetic OR3 operator having 17 base pairs in length and with its 9 bp fragment has been studied using the circular dichroism (CD) method. In both cases, a considerable change in the CD of the samples was found in the region 260-300 nm upon the addition of the cro protein. The stoichiometry obtained by the CD titration was identical for OR3 and its 9 bp fragment: one duplex per dimeric cro. NaCl addition makes the complexes dissociate so that the 9 bp fragment becomes free at [NaCl] greater than 0.2 M while the whole OR3 becomes free at [NaCl] greater than 0.5 M. The CD spectra of both the free duplexes show a typical B-form conservative pattern with a positive CD band (270 nm) and a negative one (250 nm). The specific complexing of both the duplexes results in a substantial CD depression in the positive band. The most pronounced effect occurs at 280 nm. This spectral change is quite distinct from those in the B to A transition and in the non-cooperative winding of the DNA within the B-family of forms. The interaction of the cro protein with the non-operator DNAs, calf thymus DNA and a synthetic 10 bp duplex, reveals no visible CD changes at all. An inference is drawn that the CD change in the specific complexes is mainly due to the induced CD in tyr-26 upon its interaction with a specific base pair in the operator or its fragment, the operator DNA conformation being conserved in a B-like form as a whole.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
16.
V I Ivanov L E Minchenkova A K Schyolkina B K Chernov A P Yartsev M P Kirpichnikov 《Journal of biomolecular structure & dynamics》1985,3(3):521-527
Conformations of the synthetic deoxyoligonucleotide 17 base pairs long, which is an OR3 operator of lambda phage, and of its 9-b.p. fragment were studied by the circular dichroism method (CD). The regions of stability of the double-stranded state were determined for these duplexes. A comparison of the CD spectra for these oligonucleotides with the CD for a lengthy DNA showed the conformation of these short DNA pieces to belong to the B-family. A cooperative change in the CD spectra is observed in trifluoroethanol (TFE) solutions at a TFE concentration specific for each oligonucleotide, which is supposed to stem from a B to A transition. The length of the fragment was found to affect the ability for the B-A transition. The transition into the A form is hindered by 13% TFE for the short 9-nucleotide in comparison with the 17-nucleotide. We suggest that this is due to the B form stabilization by terminal base pairs (B-phility of the ends). 相似文献
17.
Athanas I. Boyanov Boris G. Tenchov Rumiana D. Koynova Kamen S. Koumanov 《生物化学与生物物理学报:生物膜》1983,732(3):711-713
dl-Dipalmitoylphosphatidylcholine multilamellar vesicle suspensions were examined by the method of differential scanning calorimetry. A lack of the subtransition at 18°C was established. Such a subtransition is characteristic for l-dipalmitoylphosphatidylcholine suspensions. This lack is supposed to be the result of the impossibility of the racemic phospholipid mixture to form the low-temperature crystal structure Lc. 相似文献
18.
M K Pulatova D E Filatov T G Shliakova V L Sharygin V P Beletski? G A Chernov 《Izvestiia Akademii nauk SSSR. Seriia biologicheskaia》1992,(2):215-233
The study deals with the mechanism of organism's adaptive responses to the effect of radiation in widely ranging dose. Post-irradiation metabolic changes were evaluated in canine blood as well as in murine blood, spleen, bone marrow and liver using the EPR spectroscopy. It was shown that the dynamics of changes in transferrin and ceruloplasmin pools and ribonucleotide reductase activity were phase-dependent with the maxima at the 2nd, 6th and 10-12th days after irradiation. Such dynamics was observed at various irradiation doses applied. The data allow us to suggest that the nonspecific compensatory--adaptive reactions of organisms develop as the response to irradiation. The dose-response function of the reaction intensity was found to be linear. The shape of the dose-response curve indicates that the minimum response of organism depends on the dose linearly up to 3.2 Gy (for dogs) as well as the maximum one. However, in the case of low-dose irradiation (0.25 or 0.5 Gy) there were deviations of maximum responses from the linearity, i.e. the amplification of the amplitude of compensatory adaptive reactions. These effect were shown to be dependent upon initial individual characteristics of animal blood and to be related to the "depressed" or "activated" state of organism prior to irradiation. The ribonucleotide reductase activity was measured in bone marrow and spleen of animals by the EPR method. The nature of non-repairable DNA damage is discussed in view of the inactivation of ribonucleotide reductase. 相似文献
19.
Boris Blumenstein Isaac Breslav Michael Bar-Eli Gershon Tenenbaum Yitzhak Weinstein 《Applied psychophysiology and biofeedback》1995,20(2):169-183
The purpose of the present study was to examine whether breathing pattern may be used as a reliable index for the effectiveness of techniques applied for the regulation of mental states. Heart rate (HR), breathing pattern, galvanic skin response (GSR), and electromyogram (EMG) of the frontalis muscle were measured in 39 male and female subjects aged 18–25 years during 10-minute treatment with relaxation technique (autogenic training and/or music) followed by 10 minutes of imagery training. In the first 7 sessions biofeedback (BFB) was not included, while during the last 6 sessions BFB was introduced and utilized by the subjects. Relaxation (music or autogenic training) led to a decrease in breathing frequency, attributed to lengthening of expiration time, as well as reduced HR, GSR, and frontalis EMG response. In most instances imagery training was related to an increase in these indices. Specifically, significant tachypnea was observed during imagery of sprint running. In most cases BFB substantially augmented the physiological responses. In conclusion, our data suggest that, compared with HR, GSR, and EMG responses, the breathing pattern is at least as sensitive to the mental techniques employed, and may be useful as a psychophysiological index for diagnosis and testing, especially in sport practice. 相似文献
20.
Vita Peri Boris Ajdukovic Paul Holland Balwant S. Tuana 《Molecular and cellular biochemistry》1994,130(1):57-65
Dystrophin is a high molecular weight protein present at low abundance in skeletal, cardiac and smooth muscle and in trace amounts in brain. In skeletal muscle, dystrophin is uniformly distributed along the inner surface of the plasma membrane. Biochemical fractionation studies have shown that all detectable skeletal muscle dystrophin is tightly associated with a complex of wheat germ agglutinin (WGA)-binding and concanavalin A (Con A) binding sarcolemmal glycoproteins. Absence of dystrophin is the primary biochemical defect in patients with Duchenne muscular dystrophy and leads to segmental necrosis of their skeletal myofibers. Although present in similar amounts in normal cardiac and skeletal muscle, the absence of dystrophin from cardiac muscle has less severe effects on the survival of cardiac cells. We have therefore examined whether there are differences in the properties of cardiac and skeletal dystrophin. We report that in contrast to skeletal muscle, cardiac dystrophin is distributed between distinct pools: a soluble cytoplasmic pool, a membrane-bound pool not associated with WGA-binding glycoproteins and a membrane-bound pool associated with WGA-binding glycoproteins. Cardiac dystrophin was not associated with any Con A binding glycoproteins. Immunohistochemical localization studies in isolated ventricular myocytes reveal a distinct punctate staining pattern for dystrophin, approximating to the level of the transverse tubule/Z-line and contrasting with the uniform sarcolemmal staining reported for skeletal muscle fibers. The distinct properties of cardiac dystrophin suggest unique roles for this protein in cardiac versus skeletal muscle function.Abbreviations Dys
Dystrophin
- T-tubule
Transverse tubule
- SDS-PAGE
Sodium Dodecyl Sulphate-Polyacrylamide Gel Electrophoresis
- WGA
Wheat Germ Agglutinin
- Con A
Concanavalin A
- DHP
Dihydropyridine receptor
- FITC
Fluorescein Isothiocyanate Conjugate
- NAG
N-Acetyl-D-Glucosamine
- NP-40
NONIDET P-40
- PBS
Phosphate-Buffered Saline
- TBST
Tris Buffered Saline-Tween 相似文献