Steve needed to use a special oscilloscope to achieve his goal; this was only available at the cyclotron lab at Urbana, Illinois, and that too S3I-201 ic50 only at nighttime. Steve did not hesitate to work from midnight until
8 in the morning every day during that period. There, he worked all night for almost 6 months. His adventurous spirit and his dedicated work paid off. Steve made the first direct measurements of the lifetime of fluorescence not only from chlorophyll in solution, but from chlorophyll a in suspensions of the red alga Porphyridium, the green alga Chlorella, and the cyanobacterium Anacystis (Brody 1956, 1957; Brody and Rabinowitch 1957; Rabinowitch and Brody 1958). It is important to mention that independent of Brody’s work at Urbana, Illinois, Alexander Terenin’s famous laboratory at Leningrad University had also built an instrument, that had used a different method, the so-called
phase method, and there, Dmitrievsky et al. (1957) also measured the chlorophyll a fluorescence lifetime in vivo (see Borisov 2003). The lifetime of chlorophyll a fluorescence was found to be in the range of 1 to 1.5 ns in photosynthetic systems, and this was almost 4–5 times click here shorter than for chlorophyll a in solutions. Both KU-60019 mw research groups at Urbana and in Leningrad (St. Petersburg) concluded that the primary reaction of photosynthesis must be through the singlet-excited state of chlorophyll. Later my research group, and that of many others, have extended these lifetimes of fluorescence measurements; see an early review by Jursinic and Govindjee (1979). Another first in the field of photosynthesis
was then the measurement of the 3-mercaptopyruvate sulfurtransferase time (and thus, the rate) of excitation energy transfer from the orange-red pigment phycoerythrin to chlorophyll a in the red alga Porphyridium cruentum (see Brody 1958, 1960; Rabinowitch and Brody 1958; Brody and Rabinowitch 1959). When excited by green light, absorbed by phycoerythrin, the measured time for energy transfer was ~0.5 ns. Much has progressed since then, but this measurement remains the first in the field. (For excitation energy transfer, see e.g., Clegg et al. 2010; Dutton 1997; Duysens 1952; French and Young 1952; Porter et al. 1978.) As mentioned in the Introduction, Steve made still another discovery by using 77 K (liquid nitrogen temperature) spectroscopy after thinking about the obvious—that at low temperature biochemistry stops. Brody (1958) discovered a brand new emission band at 720 nm (F720). Steve had thought then that it was from a “chlorophyll dimer” (perhaps, the reaction center of Photosystem I, what is called P700); it is now known to originate from antenna chlorophyll a complex in Photosystem I. At 77 K, another band at 696 nm (F696) was discovered independently in 1963 in several laboratories (including my (G) own and that of Steve Brody) (see reviews in: Govindjee et al.