Unravelling the Double Helix

by Gareth Williams

  7

  A WHIRLWIND FROM RUSSIA

  Albrecht Kossel was not the first European to be honoured with an invitation to deliver a Harvey Lecture in New York. Three years earlier, one of the very first Harvey lecturers had been a man who personified the diversity of the Old World: Lithuanian by birth, educated in Russia, Germany and Switzerland, fluent in four languages. By coincidence, he was a near contemporary of nuclein, having been born a few weeks after its discovery. As a further coincidence, he had trained in Marburg – where his mentor had been Albrecht Kossel, and where he too had been gripped by Miescher’s peculiar molecule.

  Fishel Aronovich Levin was born into a family of staunch Lithuanian Jews on 23 February 1869. He grew up in Zagaré, a small town near the Latvian border which was renowned for its cherries and its seven synagogues. The family later moved to Petrograd (St Petersburg), where – unusually for a Jew – Fishel won a place to study medicine at the Imperial Military Medical-Surgical Academy. The Academy provided him with wonderful opportunities: the rank of captain in the Russian Army, chemistry lectures from Alexander Borodin (the doctor-scientist-composer who was failing to finish his opera Prince Igor) and physiology tutorials from Ivan Pavlov, world-famous for conditioned reflexes and salivating dogs.

  Shortly before Fishel completed his medical course, the Levins were overtaken by bigger events. Hatred of Jews, forever simmering beneath the surface of Russian society, erupted into a fresh wave of pogroms. The family fled before they were evicted, or worse. They followed a well-worn refugee trail across Europe and the Atlantic to the immigration sheds on Ellis Island in Upper New York Bay. En route, the Levins became Levenes, much as Zagaré later became Sagor when Lithuania was phagocytosed by Russia. Fishel Aronovich metamorphosed into the American-friendly Phoebus Aaron, although he was still known to his family and close friends by the Russian diminutive, Fedya.

  The Levenes reached New York on Independence Day, 4 July 1891. The twenty-two-year-old Phoebus was still determined to be a doctor and, later that year, made the hazardous return trip to St Petersburg to finish his training and bring his Doctor of Medicine certificate back to America. His brief medical career was just a stepping-stone to greater things. While working flat out as a doctor, he signed up as a ‘special’ student in chemistry at Columbia University in New York and impressed them so much that they gave him laboratory space to begin his own research. In 1894, he wrote a paper on the role of the nervous system in diabetes, the first of his 700-plus publications.

  Two years later, he threw in medicine for a research job at the Pathological Institute on the ironically named Welfare Island, where he acquired more papers – and tuberculosis. The infection was relatively kind to him and introduced him to his future wife, Ann Erickson, at a sanatorium in the Adirondack Mountains. His later treatment included a spell at the same open-air sanatorium in Davos where Miescher had breathed his last a couple of years earlier. Rejuvenated but not cured, Levene took off for Bern, Berlin, Munich and finally Kossel’s laboratory in Marburg. There, he shared a laboratory bench with a fellow American, Walter Jones from Johns Hopkins in Baltimore, who was a couple of years younger but just as full of himself.

  Levene was quickly infected with a virus-like passion for the ‘fantastic’ nucleic acids. So was Jones, dismissed by Levene as a plodder who sucked up to the boss. Irritatingly, Kossel favoured Jones over the headstrong Levene, whose self-directed experiments kept going wrong. Levene’s dislike of Jones steadily matured into pathological hatred, which was warmly reciprocated.

  On returning to the Pathology Institute in New York, Levene began exploring the ‘fantastic’ nucleic acids and other biochemical mysteries. His trajectory over the next three years was breathtaking. He published nearly sixty papers and blazed such a brilliant trail that he was chosen to give one of the inaugural Harvey Lectures in 1905 – an incredible achievement for a thirty-five-year-old who had spent barely five years in full-time research. His Harvey Lecture was on autolysis, the assisted suicide of aged tissues, and was dazzling.

  All this led to an offer that he could not refuse, even though there would be many occasions when both parties wished that he had. The offer took Levene to an institution where he did his greatest work on nucleic acids – and where, despite his efforts, the substance then known as ‘thymus nucleic acid’ was first identified as the stuff of genes.

  For the good of mankind

  The inspiration for this centre of excellence originally flowed from the Reverend Frederick T. Gates, ‘a brilliant dreamer and creator’ and adviser to the outrageously wealthy oil magnate, John D. Rockefeller Snr. Gates was depressed by the mediocrity of American medicine, and the sad truth that ‘medicine has no cures . . . and, as a science, has not progressed’. So he asked Rockefeller to pay for an independent medical research institute that would become the best in the world. Rockefeller, who had recently lost a much-loved grandson to scarlet fever, was quickly persuaded.

  In June 1901, after three years of negotiation and machination, the Rockefeller Institute for Medical Research was established, to huge public excitement. ‘Men of trained scientific intelligence will be enabled to devote themselves to the solution of definite problems,’ trumpeted the New York Times, adding encouragingly that ‘they may at some future time see their work grow to be a great landmark in medical science, like that of the Pasteur Institute in Paris’. The foundation stone of America’s first centre for biomedical research was laid on 5 December 1904, on an unpromising 13-acre parcel of farmland that overlooked the East River and Long Island. The next challenge was to populate the new institute with researchers who would live up to its stirring motto, Scientia pro bono humani generis (‘Science for the good of mankind’).

  The institute’s founding director was an inspired appointment: masses of high-quality publications about meningitis, dysentery (one of the bacteria responsible was named after him), plague, snake venom, etc etc.; a phenomenally hard worker who put science at the heart of medicine; and only thirty-eight years old. The casual observer might have wondered if these credentials belonged to someone else, because Dr Simon Flexner was short, quietly spoken and unassuming. However, his piercing blue eyes hinted at the ‘mind like a searchlight’ that lay behind them.

  The director’s start in life had not been auspicious. Raised in Louisville, Kentucky, Flexner dropped out of school and into unemployment. He was rescued by his father (who disciplined him by walking him through the local prison) and a job at a drugstore where there happened to be a microscope. In the evenings and by gaslight, Flexner taught himself bacteriology and microscopy, and was soon making diagnoses on samples brought in by local doctors. He went on to collect a degree in medicine from Louisville University; this had no medical faculty, and his doctor’s certificate was issued on the assumption that he would never lay hands on patients.

  In 1890, Flexner began bacteriology research at Johns Hopkins in Baltimore. He quickly cemented his reputation by nailing the cause of a meningitis outbreak which scythed through a mining town in Maryland; this involved stealing tissue samples from the body of a young woman whose parents had only allowed the post-mortem on the condition that she would be buried complete. High-profile assignments in the Philippines (1900) and a plague outbreak in San Francisco (1901) completed his résumé.

  Flexner started as Director of the Rockefeller Institute on 25 October 1902. He was always tough and sometimes fair; even his admirers described him as ‘mean and ruthless’ and ‘ruling with an iron fist’. The Rockefeller prospered spectacularly during his thirty-five-year term as director, becoming a research powerhouse that laid bare the mechanisms of disease and invented ingenious new treatments. Flexner prided himself on attracting the best scientists from around the world and giving them whatever they needed to flourish. Many were clever people who ‘might not have made outstanding careers as professors under ordinary conditions of academic life’. Put more bluntly, they were brilliant, but oddballs and misfits.

  Such w
as the framework into which Flexner brought Phoebus Levene in 1903, to lead the Rockefeller’s as yet unborn Biochemistry Department. This was a risky appointment, and not just because Levene’s smouldering tuberculosis could reignite at any moment. Levene was fiercely independent and allergic to bureaucracy, which soon set him on a collision course with the director. But Flexner had to grit his teeth and content himself with writing angry letters, because Levene turned out to be one of his best early investments.

  As the biochemistry labs were still under construction, Levene first set up shop in two houses knocked together on 50th Street. He was 50 per cent of the department’s staff, the other half being a technical ‘servant’. The department remained a two-man show until 1907, when Levene recruited Donald Van Slyke, Walter Jacobs and G.W. Heimrod. Van Slyke and Jacobs both went on to carve out highly successful careers; Heimrod was less fortunate, blinded in a lab accident a couple of years later. Finally, the embryonic department moved into their new premises on campus, and the show really took off.

  As his team expanded, so did Levene’s research interests. It was said later that he ‘left scarcely any part of biochemistry untouched, and touched nothing that he did not clarify’, but he was no butterfly; he had an uncanny intuition for where to look and how deep to dig. The parts that he touched included proteins, sugars, complicated lipids from the brain, and the substances which made his reputation – the nucleic acids.

  Levene had already published several papers on nucleic acids when he moved to the Rockefeller, but his first big discoveries came in 1909. Albrecht Kossel was gratified, because Levene identified the elusive pentose sugar in yeast nucleic acid, and worked out how it was joined to the phosphate and the base. Levene managed to chisel apart the building-blocks of the nucleic acid, releasing them in the sequence in which they were linked together: phosphate, then the sugar, and finally the base. The fragile pentose, which had not survived previous extraction methods, turned out to be a sugar that had been isolated from meat some years earlier and then forgotten.

  This pentose, diagnostic of yeast nucleic acid, was called D-ribose.

  Strength to strength

  Meanwhile, Simon Flexner had managed to get the Rockefeller Institute its own hospital. In 1907, he made headlines with a revolutionary ‘immune serum’ that saved patients dying from meningococcal meningitis. This horrific infection attacks the meninges (the membranes protecting the brain and spinal cord) and turns the normally gin-clear cerebrospinal fluid into thick, mayonnaise-like pus; 75 per cent of cases ended up on the mortuary slab.

  ‘Immune serum’ contained antibodies that target specific bacteria. It was harvested from the blood of horses which had been injected with extracts of the causative bacteria to stimulate antibody formation. These sera were good at killing bacteria in the laboratory, but real-life success was limited because the antibodies rarely reached effective levels in the patient. Flexner triumphed because his meningococcus serum was extremely potent, and his master-stroke was to inject it directly into the spinal fluid through a lumbar puncture needle. The results were extraordinary. ‘DISCOVERY BY DR FLEXNER’ was the ecstatic headline in the New York Times on 6 August 1907, explaining that a ‘CURE IS FOUND FOR MENINGITIS – WITH JOHN D’S AID’. This greatly impressed John D. Rockefeller, who was swiftly seduced by Flexner’s argument that the institute could only lead the world if the lab bench was brought to the bedside by building a fully functional hospital on the campus.

  The Rockefeller Institute Hospital admitted its first research patient on 26 October 1910. Its first director, hand-picked by Flexner, was Dr Rufus Cole, an expert in lobar pneumonia. This infection killed 200,000 Americans each year – even more than meningitis and tuberculosis – and thoroughly deserved its graphic nickname, The Captain of the Men of Death’. The bacterium responsible, the pneumococcus, was on the Rockefeller’s hit list from the very start, alongside polio and syphilis. Cole’s Pneumonia Research Ward was always filled with cases (and was quickly topped up whenever a vacancy occurred), all hoping for a treatment to snatch them back from the jaws of perdition.

  Pneumonia is ‘lobar’ when it fills at least one of the lobes of the lungs. At the time, it killed 25 per cent of its victims and was best endured without the interference of doctors. William Osler confessed that ‘we have no specific treatment’, but still devoted three pages of Principles and Practice of Medicine to current therapies – not used because they worked, but because doing something seemed better than doing nothing. The ‘treatments’ included strychnine, ice-filled skullcaps to reduce fever, injecting disinfectant into the lung, and sucking blood out of the patient. The only rational offering was opium, to relieve terminal distress.

  There was just one spark of hope. Serum from survivors of lobar pneumonia had been injected into six patients, all of whom showed ‘a decided fall in temperature’. Whether they lived or died was not made clear, but that brief remission was a hint that immune serum, like Flexner’s cure for meningitis, might eventually be used to treat lobar pneumonia. Within a few years, this new weapon was in use against the pneumococcus, but often with disappointing results.

  Although this was all happening just a stone’s throw from Phoebus Levene’s lab, it might seem a long way from the story of DNA. However, the attempts to make serum therapy work in lobar pneumonia provided a bizarre twist in the plot which later brought The Captain of the Men of Death on to centre stage – to play a role that eventually revealed what DNA really does.

  Bêtes noires

  Across the campus, life was good for Phoebus Levene. He was master of all he surveyed – his lab and, further afield, the worldwide domain of nucleic acid chemistry. Levene worked as hard as Simon Flexner, but somehow crammed in the finer things of life as well. His working day (of which there were seven each week) began at 6 a.m. with a shower, a couple of chapters of a French novel, a walk, breakfast and a brief nap before Joe Lender, his ‘lab boy’-cum-chauffeur, arrived in a limousine to drive him to the laboratory.

  Levene worked solidly through the day at the bench, or in discussion with his team, or writing at the plain desk in his office where he took lunch on his own. When he finished in the evening, Lender drove him home. The ‘lab boy’, only a few years his junior, was constantly on call and ready to drop everything if the chief decided to go to an art gallery or the opera; meanwhile, Levene’s own car gathered dust in his garage.

  A glance around Levene’s office would have revealed the ‘artistic temperament of the man’. A series of careful experiments had taken place there, not with chemical reagents but with paints, to perfect the colour scheme. The walls were crowded with fine-art reproductions, from Renaissance to ultra-modern, while ceiling-high shelves overflowed with books and photographs of colleagues and friends. The office was a metastasis of the Levenes’ house, the site of many ‘cordial gatherings’ into which books, pictures and ornaments were even more densely crammed.

  Donald Van Slyke and Walter Jacobs later captured the essence of the ‘professional man, student and artist’ who lunched alone at his desk, surrounded by art and erudition. Levene was slightly built and wiry, ‘always well-dressed but never over-dressed’, usually wearing a short, hip-length white lab coat (Figure 7.1). He carried one of the stigmata of the bench biochemist – yellow staining of his fingers, not from nicotine but the ubiquitous reagent picric acid. His hair, cut ‘rather long’ and light grey in his later years, hinted at the bohemian. Other distinguishing features were a small moustache and heavy eyebrows over ‘deep-set, dark brown and very frank eyes’. The ‘genial and kindly demeanour’ was rounded off with a ‘friendly smile’, especially when listening to others. Remnants of his Russian accent, which became heavier with excitement or anger, added a touch of the exotic.

  Figure 7.1 Phoebus Aaron Levene.

  Not everyone was treated to Levene’s ‘friendly smile’. Two men in particular were guaranteed to smash through the ‘genial and kindly demeanour’ and provoke a Russian-accented tirade. The
first was Simon Flexner, with whom Levene locked horns from the start. They mainly fought over resources, which they saw differently. Flexner refused to let money run away through the fingers of his iron fist and fined anyone who forgot to turn off a Bunsen burner overnight; Levene regarded a financial envelope as something to be crumpled up and tossed into the nearest bin. When Flexner wrote testily, ‘There is no money beyond the new budget, which cannot in any circumstances be exceeded’, Levene simply ignored him. This was the opening skirmish of a confrontation that simmered until Flexner retired from the Rockefeller in 1936. But Levene was so successful that Flexner risked mutiny in his tight ship, and let him get away with it.

  The second great irritant in Levene’s life was Walter Jones, Levene’s former bench-mate in Marburg, who had returned to Johns Hopkins. Jones was highly intelligent and productive, and an effective collaboration with Levene would have pushed nucleic acid research forward with incredible speed. Unfortunately, this would have been a marriage of minds made in hell, because – just like Levene – Jones saw himself as the world’s leading researcher on nucleic acids, knew himself to be infallible and enjoyed a good fight. Jones was well known for laying down the law (whether or not it approximated to the truth) and for his angry outbursts of such ‘high intensity . . . that a flame might burst forth at the lunch-table’.

  Their biggest disagreement was over a single carbon atom, but one that had a crucial bearing on the composition of thymus nucleic acid. Levene had identified ribose as the pentose sugar in yeast nucleic acid, but the sugar in thymus nucleic acid was still unknown. Jones isolated sugar fragments from thymus nucleic acid which appeared to come from a 6-carbon hexose, and stuck his neck out dangerously far by proclaiming that all ‘plant nucleic acids contain a pentose’, while ‘all animal nucleic acids contain a hexose’. For the benefit of colleagues who were dim or sloppy at the bench, he added: ‘These statements are universally granted, and one sufficiently alert to the possible sources of experimental error, cannot obtain results which differ from them.’