(v. t.) To fasten or bind, as with a knot; to knot together.
Example Sentences:
Unknot
Definition:
(v. t.) To free from knots; to untie.
Example Sentences:
(1) Initially, all attempts to unknot or remove the catheter failed.
(2) "Well…" His delightful press secretary, Lena, starts giggling as her boss tries to unknot himself from this contradiction.
(3) The purpose of this study was to identify possible mechanisms of resistance present in these cells by using human mdr1 and topoisomerase II DNA probes, antibodies to these gene products, and P4 phage unknotting assay for topoisomerase II activities.
(4) The extractable topoisomerase II activity of Bloom's syndrome fibroblasts, as measured by unknotting of page P4 DNA, is much more strongly inhibited by cell growth in medium containing BrdU than is that of normal fibroblasts.
(5) In the present study, we found that nuclear extracts of these sublines (approximately 50- and approximately 140-fold resistant to VM-26) required 2 and 8 times more adenosine 5'-triphosphate (ATP), respectively, to achieve half-maximal stimulation of unknotting activity compared to extracts from the sensitive cells.
(6) In the presence of 500 microM ATP, equimolar concentrations of 2-bromo-dATP, dideoxy-ATP, 2-chloro-dATP, 2-fluoro-dATP, and dideoxy-GTP nucleotide analogues inhibited the unknotting activity of the Topo II enzyme.
(7) Sensitivity of the topo II unknotting assay to inhibition by VP-16 was the same for the parent and all resistant cell lines.
(8) The phage P4-unknotting activity of nuclear extracts decreased 2-fold when AA8 cells entered into the non-cycling state, but there was no difference in sensitivity to amsacrine between log- and plateau-phase nuclear extracts.
(9) Methods are described for accurate measurement of 10-100 ng of unknotted P4 DNA.
(10) Our preliminary results demonstrate remarkable activity of Topo II with specific conversion of knotted form P4 DNA to unknotted form in human kidney cancer cells, YCR and ACHN.
(11) The conditions for the reactions of relaxation, unknotting, decatenation, and catenation were found to be similar to those observed with enzymes from other eukaryotic cells.
(12) The ATP concentration required for equivalent activity in a DNA-unknotting assay is 2- to 8-fold higher in nuclear extracts from drug-resistant cell lines as compared with the parental line.
(13) Several quinolones and antitumor compounds were tested as inhibitors of purified calf thymus topoisomerase II in unknotting, catenation, radiolabeled DNA cleavage, and quantitative nonradiolabeled cleavage assays.
(14) This method check relative Topo II activity with its conversion of knotted form P4 phage DNA to unknotted form.
(15) Regular chromic material was stronger in unknotted tensile strength and fracture load for all gauges.
(16) P4 unknotting assays of the purified nuclear type II topoisomerase in the presence of m-AMSA and VM-26 indicated that the mitochondrial and nuclear enzymes behaved similarly, although the mitochondrial enzyme appeared to be inhibited more strongly.
(17) More than 99% of the inversion products were unknotted rings.
(18) The enzyme can catenate supercoiled DNA molecules, unknot DNA, and cleave double-stranded DNA.
(19) Topoisomerase II activity in nuclear extracts, as determined by the P4 phage DNA-unknotting assay, was more easily detected and measured at lower NaCl concentrations in NCI-H69 than in NCI-H187 cells.
(20) The level of DNA topoisomerase II protein, detected by antibody staining, decreased concomitantly with a general decrease in DNA topoisomerase II unknotting activity, while DNA topoisomerase I activity was not affected.