OBITUARY: Andrey Dmitrievich Kaulen (1951-2000)

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A. D. Kaulen was born November 10, 1951 in Moscow. He graduated from high school with a Gold Medal and entered the Department of Biochemistry, Moscow State University. His postgraduate work began at the Department of Bioenergetics, Belozersky Institute of Physico-Chemical Biology. He defended his Candidate's and Doctoral dissertations, was awarded the Leninskii Komsomol Prize in science, contributed to organization of the Department of Photobiochemistry at the Belozersky Institute of Physico-Chemical Biology, and attended many international conferences and congresses. Throughout his whole scientific career, A. D. Kaulen was dedicated to the initially chosen problem, bacteriorhodopsin. He was a devoted family man--to his beloved wife, Masha, and a beautiful daughter, Sonya. He passed away so early ...

Scientific success came rather early during Andrey Kaulen's career. At the age of 22 years he became a coauthor of a work that provided an important piece of experimental evidence of the chemosmotic hypothesis of energy coupling. Several years later Peter Mitchell was awarded the Nobel Prize in chemistry for this theory. This work of A. D. Kaulen and some other articles published in Nature, PNAS, Journal of Biological Chemistry, FEBS Letters, etc. brought him into the group of 100 most frequently cited Russian authors not only in biological but also in the other sciences. Scientific success came rather early during Andrey Kaulen's career. At the age of 22 years he became a coauthor of a work that provided an important piece of experimental evidence of the chemosmotic hypothesis of energy coupling. Several years later Peter Mitchell was awarded the Nobel Prize in chemistry for this theory. This work of A. D. Kaulen and some other articles published in Nature, PNAS, Journal of Biological Chemistry, FEBS Letters, etc. brought him into the group of 100 most frequently cited Russian authors not only in biological but also in the other sciences.

Bacteriorhodopsin was the main subject of his scientific interest. Like E. coli for molecular biologists or drosophila for geneticists, bacteriorhodopsin is a classical object of bioenergetic research. It has been studied most extensively for the last two to three decades. Bacteriorhodopsin proved to be the simplest generator of transmembrane proton potential, a membrane form of convertible energy in living cells. The honor of obtaining of direct evidence of the generator function of bacteriorhodopsin belongs to A. D. Kaulen and his senior colleague, L. A. Drachev. It should be noted that collaboration between physicist Drachev and biologist Kaulen was remarkably successful. In general, collaborations between a physicist an a biologist are often very productive in modern biology (J. Watson and F. Crick are an obvious example). Indeed, the combination of powerful methods of modern physics with biological intuition makes such collaboration extraordinarily successful.

When the new phenomenon had been described, the problem of description of its molecular mechanism was put on the agenda. This problem was solved by A. D. Kaulen and L. A. Drachev in collaboration with Yu. A. Ovchinnikov and N. G. Abdulaev in Moscow and later in collaboration with H. Khorana in the USA. It should be emphasized that neither Kaulen nor Drachev visited their foreign colleagues. During this study, they did not leave their small and cozy laboratory at Moscow State University. Modified or recombinant bacteriorhodopsin samples for the collaborative research were provided by foreign colleagues, whereas experiments themselves were carried out using a unique set-up (super-fast laser + super-high-resolution electro- and spectrometers) designed by Drachev and Kaulen to trace the charge transfer trajectory inside the protein molecule. This cycle of works provided deep insight into the principles of bacteriorhodopsin functioning as a photoelectric generator, and they gained wide recognition from the international scientific community.

A. D. Kaulen also studied other representatives of the rhodopsin group of proteins (the chloride pump halorhodopsin and visual pigment rhodopsin) and other protein generators (cytochrome c oxidase and H⁺-ATPase). In collaboration with other researchers from the Department of Bioenergetics, Andrey succeeded in light-induced triggering of cytochrome c oxidase, a “dark” enzyme. It was a sophisticated experiment that provided a significant breakthrough in our understanding of the mechanism of action of this enzyme.

When Janos Lanyi, a leading American biophysicist and biochemist, was invited 1.5 years ago by the Editorial Board of Biochimica et Biophysica Acta to compile a special bacteriorhodopsin issue of the journal, he asked A. D. Kaulen to write a review for the issue. Andrey proved to be the only researcher from Russia invited to this elite club. He was writing his last review struggling with deadly disease. The review was submitted before the deadline, and it was a really heroic effort. When I read the manuscript, I realized that it was the best of Kaulen's writings. It came as no surprise that the article was accepted immediately.

Andrey continued to work until the last days of his life. He consulted postgraduate students and junior researchers; continued to be active in literature surveys, thinking, and planning experiments in bioenergetics. Two weeks before his death, Andrey told me that he would be interested in attending a bacteriorhodopsin seminar at the Belozersky Institute. At this seminar, E. Terpugov, a researcher from the Pushchino Institute of Cell Biophysics, planned to discuss new interesting data on bacteriorhodopsin. However, ...

Andrey Kaulen was my friend and coworker for more than 25 years. We planned and performed experiments, discussed results, attended conferences. Andrey was not only an extraordinarily talented researcher but also an absolutely reliable character, both in serious deeds and in details. He belonged to a rare category of crystal pure people, which are sometimes called saints. Even their mere existence among us prevents many people from exhibiting negative sides of human nature. I am happy that one day I came across Andrey Dmitrievich Kaulen. However, I regret very much that too little time was devoted to relations with such a remarkable and unique person.

My teacher, Sergey Evgen'evich Severin, said that, in his opinion, lack of spare time was a main disadvantage of the contemporary way of life.

A nice poem of Marshak says:

“How often did you meet your friends and relatives?
Only a few times,
When your leisure was quiet and easy,
And your attention was rapt”.

The last of Andrey's words were addressed to his wife. “Mashen'ka!”, he asked, “Where are we rushing off to?” I would like to readdress this prophetic question to his grieving friends.

V. P. Skulachev

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