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A Visit to the Johnson Foundation, 1968

J. Baz Jackson /

12 May 2011

I met Britton Chance in June 1968 while attending my first science conference, at Freudenstadt in Germany. I was 22. It may have been the year of youth revolt but I was still a little wary of this great baron of oxidative and photophosphorylation as he listened courteously and very carefully to what I had to say, even taking notes of our informal discussion. With my PhD supervisor, Tony Crofts, I had been working in Bristol University for twelve months on the mechanism of action of ion-transporting antibiotics in membranes from photosynthetic bacteria. By the end of our chat, Brit had recruited me into his tradition of inviting young scientists for sojourns at the Johnson Foundation.

To someone who had never been in an aircraft before, let aside flown to the United States, the arrangement to meet with Brit and Lil at Heathrow airport in November that year seemed a little flimsy. But it worked out; clutching my little pot of chilled chromatophore membranes we met up, and Brit, to me rather impressively, paid for my air ticket (very expensive in those days) without further thought. We arrived in Philadelphia in the rain, and drove immediately (of course) to the lab, actually by the non-scenic route. I was accommodated in one of Lil's appartments in West Philly, close enough to their house on Spruce Street to get occasional invitations to dinner with, at that time, six or seven young Chance children, and with Brit perfectly playing the American patriarch. I had arrived just in time for the U.S. Presidential election, and was treated to the spectacle on the Chance-family TV of Richard Nixon taking up the job. To my shame I remember little of the politics; in fact I confess I was more interested in the aquarium eel wired up by Brit to transmit its electric emissions to a small loudspeaker in the corner of the living room; for me (and perhaps others), the Eel beat Trickie Dickie.

Figure 1. Recording of electrochromic absorbance changes in chromatophore membranes. Johnson Foundation, 25th November 1968.

On Day 2, I was introduced to Brit's Dark Room, about 20 x 15 feet, with doors permanently open to his adjacent office on one side and the coffee room on the other, and stacked literally from floor to ceiling, round the sides, and in a central island, with workshop-built instruments: a three-dimensional maze of wires and boxes. Brit spent an hour setting up a triple-beam operating as a double-beam (don't ask!) for me to measure electrochromic absorbance changes in my chromatophores. The signals were displayed on a strip-chart recorder with a curved time axis (see Figure 1), making the measurement of rates of reaction an interesting challenge. Most of my experiments (including one that didn't work, and described witheringly by CP Lee as, "the experiment of the century") were performed on a stopped flow spectrophotometer, and most went well. I was grateful for Brit's forbearance when I dropped and broke a photomultiplier during a re-build. "It's only a $300 tube", he said through gritted teeth, arched eyebrows and a fair attempt at humour. But I was crushed. Of course, in those days health and safety issues were taken much more seriously in the lab than they are today. I worked next to a chap using a pulsed ruby laser to drive the photolysis of a CO-haemoprotein complex. Before each laser shot he usually (and quite loudly) counted down with a three-two-one-fire sequence, so that everyone in the dark room had a sporting chance to interrupt their own experiment, and close their eyes. It was almost foolproof.

As many will remember, it wasn't "lunch time" at the JF but "seminar time", with a plate of Tom Redmond's sandwiches and crisps and delicious(?) coffee. As with all visitors, I was required to present a seminar. I had never given one at any level before in my life, and so had the advantage of impassioned naivity. These were interesting times in bioenergetics: in a small group of laboratories around the world, it was becoming evident that Peter Mitchell's chemiosmotic hypothesis provided the answers to ox phos. In a much larger group of labs, including the Brit's domain in the JF, there were strong objections to this view. To my growing surprise, many of the objections arose from misunderstanding, for example of the nature of the proton electrochemical gradient. With my schooling from Tony Crofts and Brian Chappell, fourteen months of fairly intensive study, and reflection on, Peter's "little grey books", and some pretty sound data, I felt confident enough despite the hostile audience. Bert Pressman, a distinguished expert on mitochondrial ion transport, and his post-doc Tony Caswell, battered me repeatedly with arguments about valinomycin and nigericin interacting with squiggle-driven ion pumps, Mitsuo Nishimura, more gently about chromatophore ATP synthesis, and Brit himself about spectoscopic probes. Brit had published several papers on the pH indicator dyes, BTB and BCP, claiming that proton translocation was too slow to be an accompaniment to electron tansfer. I criticised this view: our data showed that anionic BTB was an unsuitable probe - it bound to the membranes, and its absorbance changed as it moved in response to the developing Δψ. He was, of course, impassive. When, however, I suggested that BCP was an acceptable external pH indicator, he grinned broadly and gave a loud, exaggerated sigh of relief. "Baz, it moved" became his tease for me during the rest of my visit. With the torrent of interuptions this, my first seminar, went on for over 1 and ½ hours, and only Tony Caswell walked out. Interestingly, I discovered the following day from Brit's very smart young post-doc, Maurice Montal, that he had somewhat similar similar ionophore data to ours (but on mitochondrial particles) and wanted to explain his results the way I had explained ours. However, because of the chemiosmotic framework, Brit was resistant, not to say, forbidding; I am now breaking this confidence of forty-three years. I was also cornered that day by Bert Pressman warning me that I ran the risk of being tainted by my association with Chappell and Crofts. Moreover, he said that, if you search hard and long enough, you will inevitably find a biological tissue (chromatophore membranes?) that behave in accordance with, and misguidedly prove, your hypothesis; my impressionable mind was a little troubled by these remarks.

In addition to all these great characters who were in those days working at the JF, I made other good friends, including Garry ("the Pot Man" - why did they call him that?) Strichartz, Tomoko Ohnishi and Les Dutton, a young lad from the same part of northern England as me, who told me he was planning to put together a device to measure and control redox potential in biological membranes. Two years later Brit sponsored another memorable trip for me to visit the JF, this time in Les's care, and my fling with electron transfer began.

– J. Baz Jackson