Demetilációja

Demetilációja refers to the process of removing a methyl group from a molecule. This biochemical reaction is crucial in various biological pathways, including metabolism and gene regulation. In many cases, demetilation is carried out by enzymes known as demethylases. These enzymes catalyze the transfer of the methyl group from the substrate to another molecule, often water or another acceptor.

One significant area where demetilation plays a role is in epigenetics. DNA methylation, the addition of a methyl group to DNA, is a key epigenetic mechanism that can alter gene expression without changing the underlying DNA sequence. Demetilation of DNA can therefore reactivate genes that were previously silenced. Similarly, methylation of histones, proteins around which DNA is wrapped, can also influence gene accessibility and expression. Demetilation of histones can reverse these modifications, impacting chromatin structure.

Beyond epigenetics, demetilation is involved in the metabolism of various compounds, including neurotransmitters and xenobiotics (foreign substances). For example, the breakdown of certain drugs and toxins in the liver often involves demetilation steps. The precise mechanism and biological significance of demetilation vary depending on the specific molecule and the cellular context. Understanding demetilation is important for comprehending fundamental biological processes and for developing therapeutic strategies for diseases where these pathways are disrupted.