Isolation of intact detergent-free phycobilisomes by trypsin

Phycobilisomes have been detached from red algal thylakoids by means of trypsin and purified by sucrosegradient centrifugation in the absence of detergents. These phycobilisomes have identical absorbance and fluorescence properties to phycobilisomes prepared with detergent. Their peptide composition determined by SDS-PAGE suggests that a lamellar peptide is cleaved by trypsin to release the intact phycobilisome. Subsequently trypsin attacks the 94 kDa peptide implicated [Redlinger, T. and Gantt, E. (1982) Proc. Natl. Acad. Sci. USA 79, 5542-5546] in the phycobilisome attachment.