A method to stabilize reduced and or gas-treated protein crystals by flash-cooling under a controlled atmosphere

A customized glove box for protein crystallization under a controlled atmos phere is described along with a cryogenic technique adapted to freeze prote in crystals inside the glove box and a very simple device for studying gas- protein complexes in the crystalline state at cryogenic temperatures. Using these techniques different redox states of oxygen-sensitive crystalline pr oteins have been stabilized and the interaction of hydrogenase with Xe, a m odel for the much lighter substrate molecular hydrogen, has been studied.