TPI1 Human, Active

TPI1 is a homodimeric enzyme, meaning it consists of two identical subunits. Each subunit contains 247 amino acids and forms a structure known as a TIM barrel, characterized by eight alpha helices surrounding eight beta strands . This structure is essential for the enzyme’s catalytic activity, which involves the transfer of a hydrogen atom from carbon 1 to carbon 2, facilitating the isomerization of a ketose to an aldose .

The enzyme’s active site is located in the lower loop regions of the TIM barrel, where it binds to the phosphate group of the substrate. TPI1’s efficiency is remarkable, providing a rate enhancement of 10^9 times compared to the nonenzymatic reaction .

Recombinant human TPI1 is produced using Escherichia coli expression systems, ensuring high purity and biological activity. This recombinant protein is often tagged with a His tag at the N-terminus to facilitate purification . The recombinant form retains the full-length sequence of the human enzyme, making it suitable for various applications, including SDS-PAGE, functional assays, and mass spectrometry .

TPI1 is vital for cellular energy production. By catalyzing the interconversion of DHAP and G3P, it ensures a continuous supply of intermediates for ATP generation in glycolysis. Additionally, TPI1 is involved in other metabolic pathways, such as the pentose phosphate shunt and fatty acid biosynthesis .

Mutations in the TPI1 gene can lead to triosephosphate isomerase deficiency, a rare genetic disorder characterized by hemolytic anemia and neurological dysfunction . This highlights the enzyme’s importance in maintaining normal cellular function.

Recombinant human TPI1 is widely used in research to study its structure, function, and role in metabolic diseases. It is also employed in high-throughput screening assays to identify potential inhibitors or activators that could modulate its activity for therapeutic purposes .