Tags: Protein.
Two types of inorganic diphosphatase very different in terms of both amino acid sequence and structure have been characterised to date: soluble and transmembrane proton-pumping pyrophosphatases (sPPases and H(+)-PPases respectively). sPPases are ubiquitous proteins that hydrolyse PPi to release heat whereas H+-PPases so far unidentified in animal and fungal cells couple the energy of PPi hydrolysis to proton movement across biological membranes.