Protein L Isoaspartyl Methyltransferase, also known as PIMT, is an enzyme responsible for the repair of abnormal protein structures known as isoaspartyl residues. Isoaspartyl residues can form in proteins through spontaneous alteration of aspartyl or asparaginyl residues due to the process of isomerization.
PIMT is a methyltransferase enzyme that works by transferring a methyl group from S-adenosyl-L-methionine (SAM) to the isoaspartyl residues in proteins. This methylation reaction helps to convert the isoaspartyl residues back into their original structure, which is usually aspartyl or asparaginyl residues.
The function of PIMT is crucial for maintaining the stability and functionality of proteins in living organisms. Accumulated isoaspartyl residues can disrupt the normal folding and function of proteins, leading to various diseases and age-related degenerative conditions such as Alzheimer's disease, Parkinson's disease, and arthritis.
PIMT is found in various organisms, including bacteria, plants, and animals, indicating its conservation throughout evolution. It plays a critical role in the protein quality control mechanisms, ensuring the proper repair of damaged proteins.
Deficiency or dysfunction of PIMT can result in the accumulation of isoaspartyl residues and subsequent protein misfolding, leading to disease states. Therefore, understanding the mechanisms and regulation of PIMT can provide valuable insights into therapeutic strategies for protein misfolding-associated disorders.
