Photosynth Res (2014) 120:347–353 DOI 10.1007/s11120-014-9971-1 NEWS REPORT Alexander Abramovich Krasnovsky (1913–1993): 100th birth anniversary in Moscow, Russia N. V. Karapetyan • Govindjee Received: 15 December 2013 / Accepted: 31 December 2013 / Published online: 29 January 2014 Ó Springer Science+Business Media Dordrecht 2014 Abstract We provide here a brief News Report on the Introduction 100th birth anniversary of Academician Alexander Abra- movich Krasnovsky, one of the greatest photobiochemists During October 10–11, 2013, an International Conference of our time, who was born on August 26, 1913 and died on ‘‘Photobiochemistry: Problems and Perspectives’’ was May 16, 1993. We provide here a short description of his held at the Russian Academy of Sciences in honor of the research, followed by some photographs. He was a pio- 100th birth anniversary of Academician Alexander Ab- neering intellectual in the area of chlorophyll photochem- ramovich Krasnovsky. He was a full member of the istry, and was always ahead of his time; he, indeed, was a Russian Academy of Sciences, and Professor of the remarkable human being. Moscow State University. Krasnovsky was a great sci- entist, who is well known for his scientific achievements, Keywords Alexander Abramovich Krasnovsky Á Chlorophyll Á Krasnovsky reaction Á Photobiochemistry Á Photochemistry We thank George C. Papageorgiou (of Greece) for reading and editing this manuscript before its publication. He wrote’’ This document quite effectively evokes the outstanding personality of Academician Krasnovsky, both as a pioneering intellectual in the field of chlorophyll photochemistry and photosynthesis, and also as a remarkable human being.’’ N. V. Karapetyan (&) A.N. Bach Institute of Biochemistry, Russian Academy of Sciences, Leninsky pr. 33, 119071 Moscow, Russia e-mail: [email protected] Govindjee Department of Biochemistry, Center of Biophysics and Quantitative Biology, and Department of Plant Biology, University of Illinois at Urbana-Champaign, 265 Morrill Hall, MC-116, 505 South Goodwin Avenue, Urbana, IL 61801-3707, USA e-mail: [email protected] Fig. 1 Academician Alexander Abramovich Krasnovsky in his office 123 348 Photosynth Res (2014) 120:347–353 which accelerated the understanding of the mechanism of habilitation (D. Sc., Biology), after his outstanding studies primary steps of photosynthesis. He was the initiator of on photoreactions of chlorophyll in vitro; the title of this photochemical studies of photosynthesis in Russia. He thesis was Investigation of photochemical reactions of was one of the major pioneers of the idea that only by photosynthesis, whereas the title of his classic paper was using physical and chemical methods, one can elucidate Reversible photochemical reduction of chlorophyll by the principles of light energy conversion in photosyn- ascorbic acid; it was published in 1948 (Krasnovsky 1948). thesis. Figure 1 shows a photograph of Academician In this paper, he observed photoreduction of chlorophyll, Alexander Abramovich Krasnovsky. accompanied by the formation of an intermediate, absorbing in the green region of spectrum (the so-called pink chlorophyll), which was reversible in the dark, A.A. Krasnovsky, Krasnovsky reaction, and beyond regenerating the initial chlorophyll. This photoreaction became known as ‘‘Krasnovsky Reaction’’ in the photo- Alexander Abramovich Krasnovsky was born on August synthesis literature. Similar photoactivity was also obtained 26, 1913 in Odessa, but in 1921 he moved with his family for bacteriochlorophyll, pheophytin, and protochlorophyll to Moscow, Russia. There he studied at elementary and (see Krasnovsky 1965). The reversible photooxidation of secondary schools, and attended special chemistry classes. various chlorophylls in model systems was also found; Already in 1931, he began working at a chemical factory. these data have been accepted as the first experimental While still working, he graduated from the Moscow Insti- evidence for photoinduced redox activity of chlorophyll tute of Chemical Technology, in 1937, and became a post- and its possible role in the primary reactions of photo- graduate student at the same Institute. He obtained his synthesis. Krasnovsky and his coworkers showed that Ph.D. (Candidate Dissertation), in Chemistry, in 1940, after chlorophyll is involved in photosynthesis, not only for doing research on photochemistry of titanium dioxide, light-harvesting, but also in electron transport as a donor or titled: Investigation of photosensitization action of titanium an acceptor. However, the details of the partners were not dioxide in dye films. From 1944 to his last days, he worked clear at that time. at the Aleksey Nikolaevich Bach Institute of Biochemistry The 1955–1965 was a period of major discoveries in of the USSR (Union of Soviet Socialist Republic) Acad- photosynthesis; we may say that it provided revolution in emy of Sciences (now Russian Academy of Sciences). This our thinking about the mechanism of photosynthesis: institute was launched on December 18, 1934, and in Emerson Enhancement Effect was discovered in photo- addition to Bach, Alexander Ivanovich Oparin (best known synthesis that led to the concept of two-pigment systems for the theory on the origin and early evolution of life) was and two light reactions, and by 1961, the so-called one of the two founders. For quite a long time, Krasnovsky Z-scheme of photosynthesis was established (for refer- served as the head of the Laboratory of Photobiochemistry. ences, see Govindjee and Krogmann 2004). A key event Krasnovsky’s research and contributions are best was the elucidation of the mechanism of chlorophyll par- described by himself in many reviews (see Krasnovsky ticipation in that process. In 1956 two important papers 1948, 1960, 1965, 1972, 1977, 1979, 1985a, 1985b, 1992). were published on this subject. Kok (1956), in the Neth- His lifetime journey in photosynthesis is described won- erlands, discovered that a small number of chlorophyll derfully well in an invited article that was first written in molecules (less than 1 %), characterized by light-induced Russian by Acad. A.A. Krasnovsky, and then translated absorbance changes at 700 nm, are involved in redox in English, edited, and published later by his son transitions, representing the energy trap (the reaction cen- A.A. Krasnovsky, Jr. (1997). ter). The other paper was from the research group of The main goal of his laboratory was the study of the Eugene Rabinowitch in USA (Coleman et al. 1956). Here, mechanisms of harvesting of solar energy by photosyn- ‘light-minus-dark’ difference spectrum reflecting changes, thesis. It was already known that light energy triggers in spectral region of chlorophyll absorption with a maxi- redox reactions in chlorophyll molecules, but the mecha- mum at 680 nm was observed. In 1963, Krasnovsky and nism of that phenomenon was unclear (see Rabinowitch coworkers (Karapetyan et al. 1963) and Rubinstein and 1945, 1951, 1956). Rabinowitch and Weiss (1936), as well Rabinowitch (1963) showed that light-induced changes, as Porret and Rabinowitch (1937), had observed reversible observed in Coleman et al. (1956), were due to changes in oxidation of chlorophyll in solutions. The single-minded fluorescence excited by the measuring beam. The idea goal of Krasnovsky in photosynthesis research was to about redox transitions of small amount of chlorophyll understand how the molecule of chlorophyll participates in (called later as a primary electron donor in reaction center) photosynthesis. In 1948, Krasnovsky obtained his in oxygenic photosynthesis was soon established, an idea 123 Photosynth Res (2014) 120:347–353 349 that we owe to Duysens (1952) for the reaction center in bacterial photosynthesis. Later the mechanism of the pri- mary charge separation in the photosynthetic reaction centers was established in the studies of Krasnovsky and his colleagues. It was shown that bacteriopheophytin is the primary electron acceptor in photo-induced charge sepa- ration in the reaction centers of purple bacteria (Shuvalov et al. 1976; Klimov et al. 1976), pheophytin in the reaction centers of PSII (Klimov et al. 1977), and chlorophyll a in the reaction centers of PSI (Fenton et al. 1979; Nuijs et al. 1986; Shuvalov et al. 1986; also see Wasielewski et al. 1987). Krasnovsky suggested that chlorophyll aggregation may Fig. 2 One of the paintings of A.A. Krasnovsky: ‘‘Moscow River be one of the important factors controlling the formation of near Zvenigorod (Moscow region)’’. Source Archives of the Kras- different chlorophyll forms in chloroplasts. Low tempera- novsky family; courtesy of A.A. Krasnovsky, Jr ture long-wavelength fluorescence found for concentrated solution of chlorophyll a was taken to indicate that a chlorophyll aggregate may be responsible for long-wave Institute of the Basic Problems of Biology, Russian emission (see a review by Krasnovsky 1992). Long- Academy of Sciences, for short RAS) in Pushchino, Mos- wavelength chlorophylls were observed in vivo for the first cow Region. time in green bean leaves as an emission band at 730 nm in Krasnovsky was well known as a pioneer and was one of the 77 K fluorescence spectra that was related to the the top scientists among international photosynthesis aggregated chlorophyll (Litvin and Krasnovsky 1957). The researchers. He delivered his lectures with great poise at long-wavelength emission, discovered by Brody (1958)in many international meetings. When Warren Butler met in the green alga Chlorella, was ascribed by him to