This invention provides a new class of enhanced apyrases (EN-apyrases) with superior pharmacokinetic, pharmacodynamic, and pharmacochemical properties and which can be purified using simplified procedures. The invention further provides constructs for transforming a cell to produce these EN-apyrases. The EN-apyrase construct comprises sequences encoding a signal sequence, a linker, and a soluble apyrase. Also provided are preparations of apyrases and methods for producing apyrase in culture cells and purification thereof.