Improved purification and N‐terminal sequence of the 33‐kDa protein in spinach PS II

Significant improvement was attained in the purification of a peripheral 33‐kDa protein from spinach chloroplasts by the use of butanol/water phase partitioning. Over 30% of the 33‐kDa protein in the chloroplasts was isolated in a short time. The amino acid sequence for the first 37 residues from the N‐terminus was determined by the automated sequencing of the purified protein.