transferaasi

Transferaasi, or transferase in Finnish, refers to a class of enzymes that catalyze the transfer of a functional group from one molecule (the donor) to another (the acceptor). In the Enzyme Commission (EC) system, transferases are classified as EC class 2. They facilitate the transfer of groups such as methyl, glycosyl, acyl, amino, or phosphate groups, enabling a wide range of biosynthetic and metabolic processes.

Subtypes of transferases include aminotransferases (transaminases), kinases (phosphotransferases), glycosyltransferases, acyltransferases, and methyltransferases, among others. The identity of the transferred group and the donor–acceptor pair determines the enzyme’s name and EC number. Mechanistically, many transferases rely on cofactors or specific donor substrates; for example, transaminases commonly require pyridoxal phosphate, kinases typically use ATP as the phosphate donor, and some glycosyltransferases use UDP-sugars as donors.

Function and significance: Transferases are essential for amino acid metabolism, nucleotide and energy metabolism, post-translational modification of proteins, DNA and RNA modification, and the construction or remodeling of cellular structures. They enable biosynthesis, catabolism, signaling, and detoxification processes across organisms.

Examples: Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) are aminotransferases that transfer amino groups. Kinases such as hexokinase transfer phosphate groups. DNA methyltransferases transfer methyl groups to cytosine residues in DNA, influencing gene expression.

Clinical and research relevance: Abnormal transferase activity can indicate disease states, while transferases are widely used in biotechnology and metabolic engineering to modify substrates and pathways. The enzyme classification system provides standardized naming and grouping for study.