RETENTION OF BACTERIORHODOPSIN ACTIVITY IN DRIED SOL-GEL GLASS

The D96N mutant form of bacteriorhodopsin (bR) purple membrane fragmen ts isolated from Halobacterium salinarium has been entrapped in sol-ge l glass and dried. The photo-activity of the bR was monitored during d rying over a period of 60 days. The entrapped bR was initially dried a t 4 degrees C followed by room temperature storage. Samples showing co nstant activity after storage at 4 degrees C lost further activity at room temperature, eventually reaching a level where the activity remai ned constant. Upon further drying at 100 degrees C in a vacuum oven th e glass lost an additional 11.4 +/- 1.3% weight and all remaining acti vity.