8-oxo-2'-deoxyguanosine

8-oxo-2'-deoxyguanosine

8-oxo-2'-deoxyguanosine (8-oxo-dG) is a modified form of the nucleoside 2'-deoxyguanosine, which is one of the four building blocks of DNA. It is a common marker of oxidative stress and DNA damage in cells.

Structure and Formation

8-oxo-2'-deoxyguanosine is formed when the guanine base in DNA is oxidized, typically by reactive oxygen species (ROS). The oxidation occurs at the C8 position of the guanine base, resulting in the addition of an oxygen atom, which alters its chemical structure and properties.

Biological Significance

The presence of 8-oxo-dG in DNA is significant because it can lead to mutations during DNA replication. The oxidized guanine can mispair with adenine instead of cytosine, leading to a G:C to T:A transversion mutation. This type of mutation is implicated in various diseases, including cancer.

Detection and Measurement

8-oxo-2'-deoxyguanosine can be measured in biological samples using techniques such as high-performance liquid chromatography (HPLC) coupled with electrochemical detection, or by using mass spectrometry. These methods allow researchers to quantify the level of oxidative DNA damage in cells and tissues.

Role in Disease

Elevated levels of 8-oxo-dG have been associated with a variety of diseases, including cancer, neurodegenerative diseases, and cardiovascular diseases. It serves as a biomarker for oxidative stress and is used in research to study the effects of antioxidants and other interventions aimed at reducing oxidative damage.

Repair Mechanisms

Cells have evolved mechanisms to repair oxidative DNA damage, including the base excision repair (BER) pathway. The enzyme 8-oxoguanine glycosylase (OGG1) is responsible for recognizing and excising 8-oxo-dG from DNA, allowing for the repair and restoration of the correct DNA sequence.

Also see

• Oxidative stress
• DNA repair
• Reactive oxygen species
• Base excision repair
• 8-oxoguanine glycosylase

Y-STR Name

Haplotype