More on Harry Tsujimoto

For a biography and more details, visit the Legacy of the Kase and Tsujimoto Family page. 

Tsujimoto’s record shows a steady stream of publications from his UC Berkeley research, spanning a period of nearly 30-years, from 1958 through 1985. Most was centered on electron transport and photophosphorylation in chloroplasts, following the pivotal discovery by the Arnon group. He made his own defining contributions to the mechanism and its interplay with the electron transport chain in these photosynthetic organelles. Tsujimoto’s work was published is a wide variety of journals in the field, on topics including but not limited to work on chloroplast thylakoid membranes, blue-green algae (cyanobacteria), and chemical uncouplers, the latter serving as tools in probing mechanistic aspects of photosynthesis and photophosphorylation.

1964 - Role of ferredoxin in photosynthetic production of oxygen and phosphorylation by chloroplasts. Proceedings of the National Academy of Science.

Photoproduction of oxygen by isolated chloroplasts was linked to the photoreduction of ferredoxin with a stoichiometry between the ferredoxin reduced and the O2 produced was 4:1. The work established that electrons from the oxidation of water and release of O2 are stoichiometrically transferred to ferredoxin, thereby unequivocally linking ferredoxin to electron transport in photosynthesis.

1966 – Differential Effects of Desaspidin on Photosynthetic Phosphorylation. Plant Physiology, the journal of the American Society of Plant Biologists.

Differential effects of the uncoupler desaspidin, a phlorobutyrophenone derivative, on whole chain water-to-ferredoxin-linked photophosphorylation, and photosystem-I only-linked (cyclic) photophosphorylation helped delineate mechanistic aspects of the two types of photophosphorylation.

1967 - Ferredoxin and Photosynthetic Phosphorylation. Nature.

The work provided evidence on the role of Ferredoxin in Photophosphorylation, i.e., the process that makes ATP, and delineates between cyclic and noncyclic electron flow, showing that high potential energy electrons from ferredoxin can go back to the electron transport chain of photosynthesis, comprising what is known today as the cyclic photophosphorylation process.

1974 - Photochemical activity and components of membrane preparations from blue-green algae. I. Coexistence of two photosystems in relation to chlorophyll a and removal of phycocyanin. Biochimica et Biophysica Acta (Bioenergetics).

The work measured action spectra and the quantum efficiency of photosynthesis in blue-green algae and demonstrated the function of both Photosystem I and Photosystem II in phycocyanin-devoid thylakoid membranes of these microorganisms.

Tasios Melis,  inaugural Grace Kase and Harry Y. Tsujimoto Chancellor’s Chair

As a UC Berkeley assistant professor in the early 1980’s, I overlapped, interacted with, and personally knew Harry Tsujimoto, who was then a senior research scientist (Specialist) in the department, in affiliation with the Arnon group.  I also met Ms. Grace Kase on a couple of incidental occasions. My perception of Harry was that of a quietly efficient and successful departmental associate. He knew how to get things done.

Fast forward, I saw Harry again some 20-years after his retirement, in the early years of the endowed Tsujimoto Lectures. Harry himself attended a few of the 12:10-1:00 pm events, incognito. He would arrive and be seated by 12:00 noon in the center of the auditorium. I always joined him in the audience and would engage in small talk prior to the Lecture, about matters of the University, the department in its “reorganized” configuration, and such. Harry specifically wanted to know of the organizational aspects of the Tsujimoto and Buchanan Lectures, both of which are endowed by the Grace Kase and Harry Tsujimoto Foundation (the K/T Foundation). He wanted to know how these were received by the students, the postdocs, and the department at large, and their impact on the programmatic activities of Plant and Microbial Biology. I was happy to oblige him with the information. He was pleased to know the value of the K/T Foundation endowments to the department. 

A testament to Harry’s modesty: Twenty years after his retirement, the reorganization of the biological sciences on campus, and the inevitable turnover and change in personnel, no one seemed to recognize that Harry Tsujimoto was in the audience, although it was the Tsujimoto Lecture with graduate student introductory attributes to him. Harry strongly preferred it this way. Although invited to, he never attended the PMB reception that typically follows the Tsujimoto Lecture, preferring to shake hands in a ‘thank you and goodbye’ note, and depart at the end of the seminar. Regardless, I could tell that Harry was pleased to know there is a University Lecture in his name.