Knowledge of an enzyme's resistance to high temperatures is especially beneficial in protein purification. In the procedure of heat denaturation, one can subject a mixture of proteins to high temperatures, which will result in the denaturation of proteins that are not thermostable, and the isolation of the protein that is thermodynamically stable. One notable example of this is found in the purification of alkaline phosphatase from the hyperthermophile "Pyrococcus abyssi". This enzyme is known for being heat stable at temperatures greater than 95 °C, and therefore can be partially purified by heating when heterologously expressed in "E. coli". The increase in temperature causes the "E. coli" proteins to precipitate, while the "P. abyssi" alkaline phosphatase remains stably in solution.