The discovery and function of plastocyanin: A personal account.

A brief autobiographical account is presented of the early research that led to the discovery of the copper protein plastocyanin and the identification of its function as an electron carrier in plant photosynthesis. A discussion follows of different approaches employed for the determination of the functional site of plastocyanin in relation to cytochrome f. A summary is provided of a heated controversy about the involvement of two or three light reactions in photosynthesis and an experiment is described that has contributed to resolution of the controversy through the identification of the functional site of plastocyanin. An early history of photosynthesis research in Japan is also discussed.