THTPA Human

The human recombinant ThTPase is a highly specific enzyme with a molecular weight of approximately 25 kDa . It has been cloned and expressed in Escherichia coli (E. coli) for large-scale production and purification . The recombinant enzyme exhibits kinetic properties similar to the native human enzyme, indicating its functional integrity .

ThTPase requires Mg²⁺ ions for its activity, while Ca²⁺ ions inhibit the enzyme by competing with Mg²⁺ . The enzyme shows maximum activity at pH 8.5 and very low activity at pH 6.0 . Interestingly, Zn²⁺ ions inhibit ThTPase at micromolar concentrations at pH 8.0 but activate it at pH 6.0 .

ThTPase exhibits nearly absolute specificity for ThTP, with a catalytic efficiency that is 10⁴ times higher for ThTP than for ATP . This specificity is crucial for its role in regulating ThTP levels in cells. The enzyme’s activity is influenced by various factors, including pH and the presence of metal ions .

The secondary structure of ThTPase, as determined by Fourier-transform infrared spectroscopy, is predominantly composed of β-sheet and α-helix structures . This structural information is essential for understanding the enzyme’s function and stability.

ThTPase is an important regulator of ThTP levels in human tissues. ThTP levels are generally higher in humans compared to rodents, likely due to the less active 25-kDa ThTPase in humans . The enzyme’s role in ThTP metabolism suggests its potential involvement in various physiological processes, including energy metabolism and signal transduction.

The study of human recombinant ThTPase has provided valuable insights into its structure, function, and catalytic properties. This knowledge is essential for developing potential therapeutic applications, such as targeting ThTPase in diseases related to thiamine metabolism.