Scientist, Staff, Sr
Virol & Micro: Zechiedrich
Baylor College of Medicine
Houston, TX, US

Professional Statement

Supercoiled DNA Minicircles for probing DNA structure, DNA topoisomerases and as a vector for gene therapy (Minivectors)

I have developed a patented protocol to generate milligram quantities of supercoiled minicircle DNA, as small as 250 bp. Using these DNA minicircles I am able to precisely determine the supercoiling dependence of topoisomerase binding and additionally elucidate the mechanism through which DNA topoisomerases recognize their supercoiled DNA substrate and determine where to act. These minicircles also provide a unique insight into the structure of supercoiled DNA, including previously unappreciated differences between overwound and underwound DNA.

In addition, I have been exploring the possibility of using supercoiled minicircles as a vector for gene therapy. Minivectors are transfected with much higher efficiency than larger plasmid vectors, are resistant to shear forces and nucleases encountered during delivery and are able to mediate gene knockdown. Based on these findings Minivector DNA holds great promise as a new gene therapy tool. Potential therapeutic applications of Minivectors are currently being tested in collaboration with colleagues at Baylor College of Medicine.


Poster Prize, 11th Structural Biology Symposium (2006), Sealy Center for Structural Biology, University of Texas Medical Branch, Galveston, Texas

1st Place, Poster Prize, Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Annual Retreat (2005), Baylor College of Medicine, Houston, Texas

Professional Societies

American Chemical Society (since 2005)

Biochemical Society (since 2008)

Invited Talks

Supercoiling in DNA minicircles: To get the big picture, think small. Banff International Research Station workshop 10w5100: Mathematics and physics of polymer entanglement (2010). The Banff Centre, Banff, Canada.

Dissecting the supercoiling dependence of topoisomerases using minicircle DNA. Topo2008: DNA Topoisomerases in Biology and Medicine (2008). John Innes Centre, Norwich, UK.

Supercoiled minicircle DNA as a probe of DNA structure and enzyme-DNA interactions. American Chemical Society southwest regional meeting (2006), Houston, Texas.

Selected Publications