AZT is used successfully as part of Highly Active Anti-Retroviral Therapy (HAART) to control the level of the human immunodeficiency virus in HIV-infected individuals. However, long-term use of AZT may lead to side-effects in some patients. David Samuels and coworkers are interested in finding out whether the toxic side effects of AZT can eventually be minimized or even eliminated. For this purpose, they have been developing a detailed computational model that allows scientists to simulate the biochemical reactions that take place when AZT is metabolized in cells, including their mitochondria, under different metabolic conditions. Drugs like AZT may interfere with DNA replication in the mitochondria, the energy factories of our cells, and can lead to potentially fatal side effects in patients undergoing HAART treatment.
Samuels, assistant professor at VBI, commented: "HAART is one of the biggest success stories in modern medicine. The goal of our work is to help improve this successful treatment by understanding the toxic effects that AZT can have in some people. There are many different ways that AZT could possibly interfere with mitochondria to cause the toxic side-effects. Our job is to model these proposed toxicity mechanisms to see which ones could actually lead to the mitochondrial defects found in AIDS patients." He added: "It is possible that no single mechanism is responsible for the toxicity, but that instead a combination of multiple effects is needed. That is the kind of problem that needs a systems biology approach."
When AZT reaches a cell, it is subject to some of the same metabolic modifications or phosphorylation events that are encountered by the four naturally occurring deoxynucleosides, the building blocks used to make DNA. However, modified AZT molecules lack a specific chemical group (a hydroxyl group) that would allow DNA replication to continue. This results in premature termination of DNA synthesis. It is thought that the triphosphorylated form of AZT can enter the mitochondrial matrix, the inner core of the mitochondrion, and disrupt the replication of mitochondrial DNA by prematurely terminating DNA synthesis.
Samuels added: "We're just starting our work. It is too early to say what the mechanism of mitochondrial toxicity of AZT is. The inhibition of deoxynucleoside metabolism is one possibility. The incorporation of AZT into mitochondrial DNA is another." He added: "The detailed computational model that we have developed should allow researchers to explore different hypotheses as to why AZT can lead to such debilitating side effects in some patients undergoing anti-retroviral treatment."
About the Virginia Bioinformatics Institute
The Virginia Bioinformatics Institute (VBI) at Virginia Tech has a research platform centered on understanding the "disease triangle" of host–pathogen–environment interactions in plants, humans and other animals. By successfully channeling innovation into transdisciplinary approaches that combine information technology and biology, researchers at VBI are addressing some of today's key challenges in the biomedical, environmental and plant sciences.
Barry Whyte | EurekAlert!
Scientists enlist engineered protein to battle the MERS virus
22.05.2017 | University of Toronto
Insight into enzyme's 3-D structure could cut biofuel costs
19.05.2017 | DOE/Los Alamos National Laboratory
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.
In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...
Dental plaque and the viscous brown slime in drainpipes are two familiar examples of bacterial biofilms. Removing such bacterial depositions from surfaces is...
For the first time, scientists have succeeded in studying the strength of hydrogen bonds in a single molecule using an atomic force microscope. Researchers from the University of Basel’s Swiss Nanoscience Institute network have reported the results in the journal Science Advances.
Hydrogen is the most common element in the universe and is an integral part of almost all organic compounds. Molecules and sections of macromolecules are...
22.05.2017 | Event News
17.05.2017 | Event News
16.05.2017 | Event News
22.05.2017 | Materials Sciences
22.05.2017 | Life Sciences
22.05.2017 | Physics and Astronomy