Disease relevance of POLY DA-DT

• A study on the unprimed poly (dA-dT) synthesis catalyzed by preparations of E. coli DNA polymerase I [1].
• While hypergammaglobulinemia, rheumatoid factor (RF) and elevated Clq binding were significantly more frequent among the anti-Ro positive group there was no increase in the frequency of anti-dsDNA antibody measured by the Farr assay or antibodies to ssDNA, dsDNA, poly dG . poly dC, poly (dA-dT) and cardiolipin measured by ELISA [2].

High impact information on POLY DA-DT

• The binding of systemic lupus erythematosus (SLE) patient serum Ig to poly dA-dT coated trays did not diminish after digestion with nuclease S1, suggesting that the synthetic polymer is an appropriate model for dsDNA [3].
• Patient and normal sera were screened for anti-dsDNA activity using poly dA-dT as antigen [3].
• Primed and unprimed synthesis of poly (dA-dT) by calf thymus DNA polymerase alpha [4].
• We conclude that psi beta 2 is not a globin pseudogene, and that the earlier investigators were probably misled by hybridization between the poly (dA-dT) stretches within the psi beta 2 region and the tails used in constructing the cDNA plasmid [5].
• The micrococcal nuclease released poly (dA-dT) core particle is found to contain a considerably narrower DNA size distribution that of the native random DNA nucleosome core (12) [6].

Biological context of POLY DA-DT

• The relative rates of hydrolysis of synthetic and natural polynucleotides was found to be: poly (U) 100, poly (dT) 33, denatured calf-thymus DNA 33, yeast tRNA 9, E. coli total RNA 6, poly (dA dT) 5, poly (A) less than 1, poly (C) less than .05, and poly (G) less than .05 [7].
• Rotational relaxation times, which are very sensitive to changes in the end-to-end length of flexible polymers, are determined from the field free dichroism decay curves of four, well defined fragments of poly (dA-dT) ranging in size from 136 to 270 base pairs [8].
• Considering a bend around a nucleosome, for example, this difference in persistence length translates to an energy difference between poly (dA-dT) and random sequence DNA of 0.17 kT/base pair or 1 kcal per 10 base pair stretch [8].
• While heterozygous mutations could be readily distinguished above background noise in 9/19 cases, it was not possible to detect alterations in a poly dA/dT tract, small triplet repeat expansions, and a 10 bp direct repeat [9].

Anatomical context of POLY DA-DT

• A study of site-specificity showed that in the presence of poly (dA/dT) the majority of Cyan betaiPr molecules form J-aggregates, while in the presence of poly (dGC/dGC) dye molecules stay mainly in monomeric form and in presence of chicken erythrocytes DNA both J-aggregate and monomeric forms of dye are present [10].

Associations of POLY DA-DT with other chemical compounds

• Biphasic helix-coil transition of the ethidium bromide-poly (dA-dT) and the propidium diiodide - poly (dA-dT) complexes. Stabilization of base-pair regions centered about the intercalation site [11].
• The androgen receptor binds about 2-fold tighter to poly(dG-dC) than to poly (dA-dT) [12].

Gene context of POLY DA-DT

• The inhibition by this drug of the mitochondrial DNA polymerase gamma activity was shown to be competitive at varying concentrations of TTP while the inhibition was of the non-competitive type at different concentrations of poly dA-dT 12-18 [13].
• Intercalation of this dye in a poly dA-dT 12-18 template-primer was studied spectrophotometrically under conditions similar to those in the in vitro DNA polymerase assay [13].

Analytical, diagnostic and therapeutic context of POLY DA-DT

• DNase-treated supernatants from these cultures were assayed for anti-dsDNA antibodies by employing a sensitive solid-phase radioimmunoassay with poly (dA-dT) as the antigen [14].
• The circular dichroism spectrum for the polymer bound to histones differs from that for the free polymer; the difference spectrum is similar to those for native and poly (dA-dT) . poly (dA-dT) core particles [15].

References