(1) However, at a 50-fold higher strand concentration, the single-stranded oligomer is gradually converted into the quadruplex.
(2) We propose a model in which duplex or hairpin forms of G-DNA are folding intermediates in the formation of either 1-, 2-, or 4-stranded quadruplex structures.
(3) There has been much recent interest in the self-association of short deoxyguanosine-rich motifs within single-stranded DNAs to generate monovalent cation modulated four-stranded helical segments called G-quadruplexes stabilized by hydrogen-bonded G-tetrad alignments.
(4) Thus the number of T residues surrounding the dG cluster might control the rigidity of the quadruplex structure.
(5) Equilibrium ultracentrifugation studies confirm that these quadruplexes are composed of two strands of d(G3T4G3).
(6) The only precedent known (to us) for a cation-specific stabilization is that seen in the quadruplex structure formed by poly I.
(7) The quadruplex, [d(TTGGGGTT)]4, is resistant to denaturation in 7 M urea, in which the Watson-Crick type d(TTGGGGTT).d(AACCCCAA) duplex dissociates.
(8) We observe well-resolved proton NMR spectra corresponding to a G-quadruplex monomer conformation predominant at 50 mM K cation concentration and a G-quadruplex dimer conformation predominant at 300 mM K cation concentration.
(9) Our results indicate that specific differences in ionic interactions can result in a switch in telomeric DNAs between intramolecular hairpin-like or quadruplex-containing species and intermolecular quadruplex structures, all of which involve G.G base pairing interactions.
(10) The possible biological function of quadruplexes is discussed.
(11) The DNA oligonucleotide d(CGCG3GCG) can form either a Watson-Crick (WC) hairpin or a parallel-stranded quadruplex structure containing six G-quartet base pair assemblies.
(12) We find that these molecules fold to form a symmetrical bimolecular and an intramolecular quadruplex, respectively.
(13) An increase in ionic strength stabilizes the single-stranded structure, so it seems to inhibit the formation of the quadruplex.
(14) Experiments on ethidium bromide binding to the oligonucleotides have shown that the oligomer anti(A-T) exists, at a low ionic strength, as a four stranded complex ("quadruplex") contains two antiparallel helices, d(A).d(T), which have a parallel orientation and are bound to one another owing to the formation of additional hydrogen bonds between nucleic acid bases.
(15) The quadruplex is stable in the presence of 40 mM K+ at micromolar DNA concentration and can be kinetically trapped as a metastable form when prepared at millimolar DNA concentration and then diluted into buffer containing 40 mM Na+.
(16) Cations stabilize the quadruplex in the order K+ greater than Ca2+ greater than Na+ greater than Mg2+ greater than Li+ and K+ greater than Rb+ greater than Cs+, indicating that K+ has an optimum ionic radius for complex formation and that ionic charge affects the extent of ion-induced stabilization.
(17) Comparison with the corresponding CD spectral characteristics suggests that the electrophoretic intensity enhancement of the intermolecular G-quadruplex band is correlated to the intensity enhancement of of the positive CD maximum at 265 nm.
(18) Similar but less dramatic enhancement of the intermolecular quadruplex band is also observed in T4.
(19) Since K+ and NH4+ are known to stabilize a parallel-stranded quadruplex structure of poly[r(I)4], we infer that the multistranded structure is a quadruplex.
(20) UV thermal denaturation curves show a single concentration-dependent transition and provide data for quantitating the thermodynamics of quadruplex formation.
Record
Definition:
(v. t.) To recall to mind; to recollect; to remember; to meditate.
(v. t.) To repeat; to recite; to sing or play.
(v. t.) To preserve the memory of, by committing to writing, to printing, to inscription, or the like; to make note of; to write or enter in a book or on parchment, for the purpose of preserving authentic evidence of; to register; to enroll; as, to record the proceedings of a court; to record historical events.
(v. i.) To reflect; to ponder.
(v. i.) To sing or repeat a tune.
(v. t.) A writing by which some act or event, or a number of acts or events, is recorded; a register; as, a record of the acts of the Hebrew kings; a record of the variations of temperature during a certain time; a family record.
(v. t.) An official contemporaneous writing by which the acts of some public body, or public officer, are recorded; as, a record of city ordinances; the records of the receiver of taxes.
(v. t.) An authentic official copy of a document which has been entered in a book, or deposited in the keeping of some officer designated by law.
(v. t.) An official contemporaneous memorandum stating the proceedings of a court of justice; a judicial record.
(v. t.) The various legal papers used in a case, together with memoranda of the proceedings of the court; as, it is not permissible to allege facts not in the record.
(v. t.) Testimony; witness; attestation.
(v. t.) That which serves to perpetuate a knowledge of acts or events; a monument; a memorial.
(v. t.) That which has been, or might be, recorded; the known facts in the course, progress, or duration of anything, as in the life of a public man; as, a politician with a good or a bad record.
(v. t.) That which has been publicly achieved in any kind of competitive sport as recorded in some authoritative manner, as the time made by a winning horse in a race.
Example Sentences:
(1) Steady-state values of cell, glucose, and cellulase concentration oxygen tension, and outlet gas oxygen partial pressure were recorded.
(2) Lucy and Ed will combine coverage of hard and breaking news with a commitment to investigative journalism, which their track record so clearly demonstrates”.
(3) Microionophoretically applied excitatory amino acids induced firing of extracellularly recorded single units in a tissue slice preparation of the mouse cochlear nucleus, and the similarly applied antagonist 2-amino-5-phosphonovalerate (2APV) was demonstrated to be a selective N-methyl-D-aspartate (NMDA) receptor antagonist.
(4) The inquiry found the law enforcement agencies routinely fail to record the professions of those whose communications data records they access under Ripa.
(5) Phenotypic relationships were examined between final score and 13 type appraisal traits and first lactation milk yield from 2935 Ayrshire, 3154 Brown Swiss, 13,110 Guernsey, 50,422 Jersey, and 924 Milking Shorthorn records.
(6) Completeness of isolation of the coronary and systemic circulations was shown by the marked difference in appearance times between the reflex hypotensive responses from catecholamine injections into the isolated coronary circulation and the direct hypertensive response from a similar injection when the circulations were connected as well as by the marked difference between the pressure pulses recorded simultaneously on both sides of the aortic balloon separating the two circulations.4.
(7) Subjects then rested supine until 10.00 h when blood was again taken, and blood pressure recorded.
(8) Sewel is also recorded complaining about the level of appearance allowances at the House of Lords .
(9) A mean difference for individual patients between the first and second recording within 5 mm Hg was observed in 49.3% and 52.1% of patients for 24-hour systolic and diastolic blood pressure, respectively.
(10) In the upper limb and facial forms of familial amyloidotic polyneuropathy first recorded in Swiss and Finns respectively, the differences in their patterns of neurological disease and ocular lesions could be the result of their amyloids deriving from proteins other than prealbumin.
(11) Since 1979, patients started on long-term lithium treatment at the Psychiatric Hospital in Risskov have been followed systematically with recording of clinical and laboratory variables before the start of treatment, after 6 and 12 months of treatment, and thereafter at yearly intervals.
(12) Polygraphic recordings during sleep were performed on 18 elderly persons (age range: 64-100 years).
(13) Richard Hill, deputy chief executive at the Homes & Communities Agency , said: "As social businesses, housing associations already have a good record of re-investing their surpluses to build new homes and improve those of their existing tenants.
(14) Several dimensions of the outcome of 86 schizophrenic patients were recorded 1 year after discharge from inpatient index-treatment to complete a prospective study concerning the course of illness (rehospitalization, symptoms, employment and social contacts).
(15) Even if it were not the case that police use a variety of tricks to keep recorded crime figures low, this data would still represent an almost meaningless measure of the extent of crime in society, for the simple reason that a huge proportion of crimes (of almost all sorts) have always gone unreported.
(16) The records of 148 geriatric patients discharged from the Royal Ottawa Hospital over an 18-month period were studied.
(17) It is suitable either for brief sampling of AP durations when recording with microelectrodes, which may impale cells intermittently, or for continuous monitoring, as with suction electrodes on intact beating hearts in situ.
(18) The records of all patients treated for thymoma in the Department of Radiotherapy of the University of Torino between 1970 and 1988 were reviewed.
(19) Both of these species belong to the serotype B. MCAs T11 and T15, the first recorded with a specificity for only sub-serotype A2 EF, were tested further against 28 sub-serotype A2 and three sub-serotype A2B2EFs from L. tropica strains.
(20) The time to make the decision and the total time are automatically recorded.