Putative name for the
enzymes produced exclusively by
extremophiles. A Good example is the S-layer protein produced by an archae that lives in temperatures up to 110 degrees centigrade (
Heliobacter pylorii).
They are often used for industrial applications such as chemosynthesis or even such commonplace uses as washing powders (thus 'biological').
Have the strange virtue of often being easier to crystallise than normal proteins since they are pH or salt stable.