Professor Peter Quinn left school in Victoria, Australia, aged 15, to train as a farmer at Dookie Agricultural College (1957–1959). After obtaining his diploma, he moved to The University of Melbourne to study agricultural science (1960–1963) and then moved to Sydney to undertake a PhD in veterinary physiology (under the supervision of I.G. White; 1964–1966). On the basis of these studies, Peter was awarded a Ford Foundation Fellowship (1967 Royal Agricultural Society, Research Fellow, University of Sydney). At the time, for some, it was preferred practice to go overseas on completion of the PhD to gain experience, and Peter was supported by a generous Population Council Fellowship to work as a Research Fellow in the Biochemistry Department at the Babraham Institute in Cambridge in the laboratory of Rex Dawson.
Owing to this varied career path, Peter was amenable to many collaborations that were often outside of the orthodox range of biological specialisms – having a talent for a multidisciplinary approach and encouraging specialists to apply their skills to topics outside their ‘comfort zone’.
Peter was a remarkably self-sufficient and determinedly independent individual. He built his own atomic absorption spectrometer, in Sydney, enabling him to carry out state-of-the-art analysis of the distribution of electrolytes across the plasma membrane of living cells. This sparked a lifetime’s interest in cell membranes, their structure and composition and barrier and transport function.
Peter moved to the USA to work as a postdoctoral fellow at Washington University in St Louis and Northwestern University in Chicago, returning to the UK in 1972 to join the Department of Biochemistry at Oxford University (working with Charles Pasternak) as a senior MRC Research Fellow and a part-time lecturer at Worcester College. In August 1974, Peter was appointed to a full-time lectureship in biochemistry at Chelsea College, London University. Here he continued the work started at Northwestern University on phosphatidylinositol turnover in the brain.
At Chelsea College, Peter collaborated with Dennis Chapman on new methods of hydrogenating unsaturated lipids. This led, in 1976, to a successful patent ‘Homogeneous Catalytic Hydrogenation’. There was no shortage of ideas in this group, and those who visited the laboratory at that time still remember the warmed plastic tanks and the multiple ‘hydrogen bombs’ dreamed up by Peter with the help of an artisan plumber.
Peter set up his own company, Polytechnology Transfer Limited, to capitalize on and exploit their own and other’s inventions. This example inspired several of his collaborators and students, with whom Peter did not hesitate to discuss his own successes and failures. These commercial pursuits ran in parallel with a particularly fruitful collaboration with Patrick Williams and Tony Brain on the structure of photosynthetic membranes and the role played by membrane lipids.
In the early 1980s, Peter became convinced that the best way to understand membrane structure–function was by direct X-ray and neutron scattering. Using the synchrotron at the Daresbury Laboratory allowed a fast rate of acquisition and temperature scanning of lipid mixtures. The high-resolution images obtained made it possible for Peter to reinterpret how the lipid structure changes with phase alterations on cycles of heating and cooling. This led to an interest in how different membrane lipids interacted with each other, as this would explain why the lipid composition was so complex. Collaborating with Rex Dawson and Robin Irvine at the Babraham Institute, NMR was used to examine mixtures of phospholipids. Later studies with the Daresbury synchrotron showed that diglycerides cause fusion of phospholipid bilayers. At that time, the dominant thought was that the structure of the membrane could only be the ‘fluid bilayer’ whose stability was assured by the amphiphilic structure of prominent unsaturated lipids. This could only be contravened by a few rare lipids forming the annulus around membrane proteins. Peter helped to undermine the dogma of ‘eternally stable’ lamellae by demonstrating the influence of proteins or enzymes that modify these membrane lipids in vivo. Inventors of nano-lipid capsules of RNA vaccines are now fully aware of the interest of non-lamellar fusogenic structures!
Peter was also intrigued by the distribution of redox components within membranes, particularly coenzyme Q10 (CoQ). With graduate students, he investigated how tocopherols partition and are arranged in membranes. They reported that biological homologues of CoQ occupied a position in a central plane of the bilayer with occasional excursions to the lipid–water interface and demonstrated that the fat-soluble vitamin E1 comprised a family of hydrocarbon compounds (referred to as tocopherols and tocotrienols) partitioned preferentially into phosphatidylcholines. This suggested its primary function was to act as a membrane antioxidant.
A grant proposal detailing this hypothesis was firmly rejected as preposterous. After this rebuff, a CoQ-VitE (Q-E cycle) driven by differences in redox potentials of the Q-E couple in water and the hydrophobic bilayer interior was demonstrated, just as Peter had predicted!
The last few years, including those when Peter’s energy was curtailed, were devoted to the study of membrane raft structures – molecular model calculations and X-ray observations confirmed the heterogeneity of sphingomyelin and cholesterol mixtures. The study of myelin sheaths and white matter will perhaps, one day, confirm the importance of this molecular scale work.
He was awarded a DSc Biochemistry from the University of London in 1980. Chelsea College subsequently amalgamated with King’s College, where Peter remained for the rest of his working life.
Publications include 10 books and more than 400 research papers on the subject of biological membranes and their constituents. Peter was an editorial board member of five international scientific journals and was invited to present and speak at over 100 scientific meetings. He was an active member of the Biochemical Society, including positions on sub-committees and Council in the 1980s and 1990s.
Peter was physically and psychologically tough. This was not only demonstrated by academic and research work, but in his life in general. He enjoyed vigorous activity, such as hiking in deserted places, like central Tasmania and Massif Central in France, where he enjoyed sharing the rich food and wines. Also sailing the rough outer Hebridean seas with his seafaring friends. We also admired his courage in maintaining a very active work schedule and online collaborations despite a long and punishing terminal illness. Peter was an enthusiastic backwoodsman, but unfortunately paid a high price for this as his Australian holiday home, with all its possessions, was destroyed in a vast bushfire in rural Victoria. But he and his wife, Christine, indefatigably upped sticks and, without fuss, transplanted to Melbourne, balancing visits there, with their life in the relative safety of central London. This courage was wonderfully sustained by his loving wife, Christine, and large family in England and Australia.
During the time that we shared our office space, I grew to admire and like him immensely. We had many useful (and sometimes heated) discussions about our research interests. On the very rare occasions that we had something to celebrate, we shared a dram or two of fine single malt!