Manganese superoxide dismutase plasmid liposomes (MnSOD-PL) confer organ-specific in vivo ionizing irradiation protection. To prepare for potential intravenous clinical trials of systemic MnSOD-PL for radioprotection in humans, plasmid and bacterial sequences were removed and a new minicircle construct was tested. Minicircle MnSOD was purified and then cotransfected into 32D cl 3 murine interle...

Recent advances in structural biochemistry have provided evidence that not only the geometric properties but also the elastic moduli of duplex DNA are strongly dependent on nucleotide sequence in a way that is not accounted for by classical rod models of the Kirchhoff type. A theory of sequence-dependent DNA elasticity is employed here to calculate the dependence of the equilibrium configuratio...

Kinetoplast DNA (kDNA) was isolated from 56 stocks of Trypanosoma cruzi isolated from human patients, animals and insects from Brazil, Venezuela, Colombia and Costa Rica. Comparison of the patterns of digested kDNA on acrylamide gels led to the grouping of several stocks into two schizodemes. Schizodeme analysis was also performed using a set of 330-bp fragments representing all the variable re...

The sequence dependence of the conformational distribution of DNA under various levels of torsional stress is an important unsolved problem. Combining theory and coarse-grained simulations shows that the DNA sequence and a structural correlation due to topology constraints of a circle are the main factors that dictate the 3D structure of a 336 bp DNA minicircle under torsional stress. We found ...

Two different RNA editing systems have been described in the kinetoplast-mitochondrion of trypanosomatid protists. The first involves the precise insertion and deletion of U residues mostly within the coding regions of maxicircle-encoded mRNAs to produce open reading frames. This editing is mediated by short overlapping complementary guide RNAs encoded in both the maxicircle and the minicircle ...

The mitochondrial DNA of Trypanosoma brucei is organized in a complex structure called the kinetoplast. In this study, we define the complete kinetoplast duplication cycle in T. brucei based on three-dimensional reconstructions from serial-section electron micrographs. This structural model was enhanced by analyses of the replication process of DNA maxi- and minicircles. Novel insights were obt...

A 6 M guanidine-HCl/0.2 M EDTA solution was used to lyse and store whole blood specimens. DNA stored in guanidine-EDTA-blood (GEB) lysate was found to be undegraded after incubation at 37 degrees C for 1 month, suggesting that this represents an appropriate reagent for transport of blood samples from the field to a laboratory for analysis. Trypanosoma cruzi kinetoplast DNA in GEB lysate can be ...

Kinetoplast DNA (kDNA), the mitochondrial genome of trypanosomes, is a catenated network containing thousands of minicircles and tens of maxicircles. The topological complexity dictates some unusual features including a topoisomerase-mediated release-and-reattachment mechanism for minicircle replication and at least six mitochondrial DNA polymerases (Pols) for kDNA transactions. Previously, we ...

Kinetoplast DNA, the mitochondrial DNA of the trypanosomatid Crithidia fasciculata, is a remarkable structure containing 5,000 topologically linked DNA minicircles. Their replication is initiated at two conserved sequences, a dodecamer, known as the universal minicircle sequence (UMS), and a hexamer, which are located at the replication origins of the minicircle L- and H-strands, respectively. ...

Replication of the kinetoplast DNA minicircle lagging (heavy (H))-strand initiates at, or near, a unique hexameric sequence (5'-ACGCCC-3') that is conserved in the minicircles of trypanosomatid species. A protein from the trypanosomatid Crithidia fasciculata binds specifically a 14-mer sequence, consisting of the complementary strand hexamer and eight flanking nucleotides at the H-strand replic...