I)in,i I(u I e trUCtur,1 sir narF 11W Irrul&^s (I.I. Cornudella, ed.)

Treballs de la SCB. Vol. 48 (1998) 2b3-270

PROTEIN RESEARCH IN CAMBRIGDE IN THE POSTWAR YEARS

SIR .1011\ U. Knxutit \\

('ontercncia inaugural del curs 1996-1997 , pronunciada a la Sala Prat de la Riba de I'IFC, el dia 22 d ' octubre de 1996.

La transcripci6 del text ha estat a carrec de Xavier Vilanova i Arantzazu Gorostiza. Universitat Auto noma de Barcelona . Bellaterra.

Ladies and gentlemen, it is a great plea- because I know that generally, active scien- sure to be hack again in Barcelona. Professor tists in any field never read papers more Guerrero mentioned that I came in 1967. Ac- than about three years old. But this is about tually, the first time I came was in 1956 for things that happened forty years ago. Of another reason, so I have been to Barcelona course, these days biochemistry, molecular a number of times, and it is a great pleasure biology and microbiology have become re- to have the opportunity of talking to the ally the same subject. So, I am going to talk Catalan Society of Biology. about sonic early biochemical research in Needless to say I did not understand Cambridge and about the beginnings of everything that Professor Guerrero said be- molecular biology. cause my knowledge of Catalan is zero, so I In spite of my title I should make at least think they were rather kind words but I am a passing reference to DNA as well as to not absolutely sure. Well, you might expect proteins. Actually, at the very beginning I from a visiting biologist to hear about some had to move for a short time away from of his own results in the field (you had a lit- Cambridge to the Royal Institution in Lon- tle of that from Professor Guerrero) but you don in the 1920's. The Royal Institution is fa- will not get it from me because I need to talk mous for its fridav-evening discourses in- to you about what is already ancient histo- tended for the general public and they ry. I ought to apologize for this, but I really began with Flumphry Davy and Faraday. have no choice because I am myself a bit old, 't'raditionally the directors of the Royal In- what is now old history. I have long retired stitution have always been experts in giving from any work of my own in the laboratory. popular lectures, specially lectures to chil- My own research was all done in the 1950's dren. In the 1920's the director was William and the early 1960's. This is just to warn you Bragg. You may know that there were two _'(J Sl{f,lUll.A (. U,W)K/:11

Braggs, father and son, and the younger ment of Biochemistry and Hopkins was Bragg, Lawrence Bragg, really thundered the first professor. the subject of the X-ray crystallography by The emergence of biochemistry from determining the substructure of a crystal physiology was not without battles and bit- containing a molecule with only two atoms terness. The old against the new. There was in it, that of sodium chloride. The Braggs a similar history in the emergence of molec- shared the Nobel Prize. The younger Bragg ular biology from biochemistry. Just to give was really very young when he got his. In you two examples of this, nay close col- fact he told me that he got the telegram league, Max Perutz, was not invited by the telling him he had won the prize when he professor of biochemistry to give any lec- was in the trenches in the First World War, tures in the department of Biochemistry and so he was quite surprised, I think. so he had to give his lectures in Professor Well, we will cone hack to the younger Keilin's laboratory which was called para- Bragg later, but now for the older Bragg. sitology. I remember too that my old friend One day Bragg, as director of the Royal In- -and he really was a friend of mine in spite stitution, was going to give a popular lec- of what I am just about to say-, Ernst Chain, ture with the title "On the imperfect crys- who of course won a Nobel Prize himself, tallization of common things". fie went was once my Chairman at a meeting on the round the young people in the lab, in the history of biochemistry. I had to give a talk research group, and told them to take X- about the history of molecular biology, so ray pictures of anything they could think Chain introduced me by saving that I was of. One of the younger students there was about to talk on a subject that did not exist Astbury. He took his first X-ray photo- because he said molecular biology is simply graph of human hair and found that it did a branch of natural products chemistry. So give an X-ray pattern. Furthermore, he you see, there were problems concerning found that if he stretched the hair, the pat- new names those days. But those battles are tern changed. This of course became really over now and, as I have already said, known as the alfa- and beta-carotene pat- there is really no difference today between terns and I believe that they really were the physiological chemistry, biochemistry, mol- first experiments in molecular biology. ecular biology and some other biological Later, by the way, Astbury also took the subjects. first X-ray pictures of DNA, but he never My own connection with biochemistry solved the structure. Bragg had another began when I was reading some natural sci- brilliant young student there in the Royal ences at Cambridge. In 1937 1 took a subject, Institution, Desmond Bernal. We will come biochemistry, and I was surpervised by back to him later. Well, that was the Royal somebody you may know the name of, Institution in the twenties, so now I think namely, Robinson. He was a lecturer in we can go back to Cambridge. So, how did physiology at the time and he told me that biochemistry begin in Cambridge? It grew he always taught people physiology previ- out of the older department of Physiology, ously but he wanted to change so he was and Gowland I lopkins had been brought going to try to teach biochemistry now, but there in 1898 to work on what was then he was going to take the same course of lec- called "chemical aspects of physiology". In tures as I was to learn the subject and he 1914 the University decided to create a thought that he probably knew very little separate department, called the depart- more than I did, so he said: zvhi/ doli't t/ou 265 PROTEIA RLS.AR ( iiL\(A:LIBRII )(L'L\ i/ILl'OSIII, IR )L IRS

development of purification methods, comic to the lab a nd I'll S how YOU what I'm1 doing the quite a bit later . I mean, I myself in my work 1111 thC' OxygC'rl diSSOClation CUrz'e Of 11aCrr10g10- myoglobin with ammo- bin?. That was my first acquaintance with used to fraccionate when I go back on it, it is a heme proteins. Well, of course, the big nium sulfate and , method and I am really quite break in Cambridge, as in other countries, very crude we ever got any crystals at all. was the war and most of the staff of the bio- surprised that was no good unless you chemistry department and others went to And indeed that concentrated protein solution do war service. Academical research had a rather course, as you probably throughout Cambridge was at a very low to work with . Of and Synge , who worked in ebb. know , Martin that, in the thirties, Things began again of course after the Cambridge earlier than chromatography , but certainly war but, even before the war ended, pro- developed a work we had no knowl- tein research in Cambridge had its real be- when I began inv use of chromatography. ginning with the appointment of Chiminal edge of or made no next step was to realize that to the professorship of biochemistry. He Well, I think the species were differ- succeeded Gowland I iopkins, who had re- proteins from different words, there was a species- tired. Chiminal came from the Imperial ent and , in other remember a conference in College in London where he had been pro- specificity . I memory of Barcroft, where fessor of biochemistry. Already when he Cambridge in came from Helsinki and was there he began with the study of the Cavannaught differences between the amino acid composition of proteins. Mod- talked about the adult sheep and fetal sheep. estly, when he came to Cambridge he did haemoglobin of worked on adult sheep and not eject the retired professor Gowland In fact I myself at one time. Hopkins from his office. lie thought he fetal sheep haemoglobins myoglobin by then it would simply build a hut outside the main When I came onto species had its own building and that was where Chiminal was clear that every They all had the same took place and it was always known as the kind of myoglobin . all had very similar "Protein hut". He went on working there molecular weight, they but they were dif- until he retired in the mid-fifties. That was amino acid compositions different kinds of crus- really the place where protein studies in ferent and produced about fifteen different Cambridge took off. tal. I think we got different animals. That But what was really known about pro- kinds of crustal from the species -specificity teins in those early days?. In the beginning clear recognition of beginning of my work on they were thought to he almost colloids, was really the crystallizing proteins namely aggregates of not very defined coin- myoglobin . Of course , of black art, it has position. Then came the notion, the discov- has always been a kind science. My advice to any- ery, that proteins did have a definite molec- never become a protein is always to say ular weight. That was due to Svedberg body tackling a new this protein through every in Sweden, using an osmotic pressure, to them : look at sure you will fInd one who did the first proper measurement of species you Can find and crystals. the molecular weight of haemoglobins which has good next stage was the de- (67000 Da). Well, the next stage perphaps Well, I think the end-groups, the amino was to realize that proteins had a definite, termination of the . That was done reproduceable amino acid composition. acid end - groups of proteins . They showed that the That was really due to Chiminal. Then came by Sanger and Porter r,i, Wl,'JO//\ ( Al \l)/il 11

same proteins from different species might British Embassy was attached to the head- have different end-groups, another exam- quarters of Jiang Jie-Shi (Chiang Kai-Slick), pie of species-specificity. Then came That was before the comunist revolution in Sanger's great work on the sequence, the China. That is why he learnt Chinese and complete amino acid sequence of insulin, why he began his studies of history and col- which of course was a very small protein, lecting books. He had one or two young but it was the first whose sequence had Chinese as his assistants, so one of them was been determined. After that of course came Chao Tse Ching. Chao arrived in Cam- the work on the three-dimensional struc- bridge in 1946 and took a B.A. degree in ture of proteins. This was the kind of devel- 1948. Then he became a graduate student of opment of ideas about proteins which had Kenneth Bailey, took his PhD, I think in really only grown at the time I am speaking 1951, and became a fellow of King's College of. Chiminal's group in biochemistry in which was Needhanm's college and I believe Cambridge played a really important role he was the first Chinese scientist to become in those developments. Besides his own a fellow of the Cambridge college. Well, his work on the amino acid composition of pro- work with Bailey was really very important. teins with people like Perry and Porter, he It was on the fragmentation of myosin and had in his group, as I have already men- the subunits of myosin, which later really tioned him, Fred Sanger. You may know provided the basis for the later discovery of that he got himself two Nobel Prizes, one the myosin light chain. He also worked on for the complete sequence of a protein, in- the size and shape of tropomyosin and a sulin, and the other for his work on devel- number of other related topics. He contin- oping methods of sequencing nucleic acids. ued this work when he returned to China. Another one that I would like to mention He played a leading part in initiating one was Kenneth Bailey. He worked first of all of the great successes of Chinese biochem- on the denaturation of proteins. He worked istry during the World War which was the on myosin, on actomvosin and he discov- total synthesis of insulin which nobody had ered tropomyosin. even attempted before that. But it was a At this point, I simply cannot resist an- tragedy for him, I think due to his western other short diversion from Cambridge. In contacts, that, when the cultural revolution fact is a diversion to China and about Ken- came, there by then both he and his wife neth Bailey's Chinese assistant, who was were members -not very enthusiastic mem- called Chao Tse Ching. He was brought to bers- but they were members of the Com- Cambridge in 1946 by Joseph Needham, munist Party, he was put into some of those who was a distinguished embryologist in chicken farms for four years and this rid his the biochemistry department before the health. After the revolution, he re-emerged war. During the war he switched to the his- and became deputy director of this institute. tory of Chinese science and technology, His health really wasn't good and in fact he which must be something like 16 volumes died only about 18 months ago. I tell the sto- now. It is a great work and the Chinese ry because he was really a rather friend of would always tell you that it is the standard mine and in fact I went to China this spring work on the history of Chinese science and, to participate in a symposium which China by the way, Needham spoke fluent Chinese arranged in the memory of Chao Tse Ching. himself. This came about because during That was in fact an important element in the the war he went to Chong-Qing, where the development of protein research in Cam- NRO11LLy RL. 1R(711A ('.IAIRKII)(;t: L1' tilt: /'(JST{i.d[t ft.IR. 'a

on the X-ray bridge. The insulin synthesis part of this ac- W.H. Taylor, who had worked younger Bragg tually happened in China. analysis of silicates with the opening re- Shortly before the war another man that when he was a magister and his take on a project I have mentioned, namely Desmond Bernal, mark to me was: 1 think you chance of success, nec- who had been in the Royal Institution, came which has absolutely no to help. So that was to Cambridge to work as a crystallographer t'rtheless I will do my best thought about pro- under the younger Bragg. The younger what the professionals I think Bragg himself Bragg had now become Cavendish Profes- tein crystallography. really believed it. I sor, that is, professor at the Cavendish Labo- was the only one who not know any- ratorv, which was the home of nuclear should say that Bragg did when this started. physics in Cambridge, and he succeeded thing much about biology crystallographer and Rutherford and J. J. Thomson. Bernal stu- fie was really a pure idea of studying dents were Max Perutz and Dorothy he was fascinated by the complicat- Hodgkin. Dorothy I lodgkin moved to Ox- proteins because he liked all the about the most ford and also got a Nobel Prize. Max Perutz ed puzzles, and this was just think of in the stayed in Cambridge. Of course the seminal complicated puzzle he could learnt was in discovery by Bernal was that, although if field. Well, all the early work I Perutz was working you just put a protein crystal on a pin and fact on proteins. Max After a little work I took pictures of it, you got almost no reflec- on horse haemoglobin. fetal sheep tions at all, but if you kept the crystal wet by have already mentioned about because it closing it in a thin glass capillary tub", haemoglobin, I picked mvoglobin had fewer sealed the ends so it kept wet, then von got a was a nice, small protein and People beautiful pattern with thousands of reflec- atomes in it than haemoglobin did. of course, but tions on it. He first demonstrated this with think of Crick as a DNA man on pro- pepsin. From that beginning originated in fact he came to our lab to work was on the Max Perutz's work on haemoglobin which teins. His first work in the lab crys- proved really to be his life's work. structure of lysozvme but he never got Crick coming The Medical Research Council Laborato- tals of it. I remember Francis morning with an ry in Cambridge began when I joined Max into the laboratory in the onion on his after the war and later we were joined by onion. He needed to rub the Human tears Francis Crick. We were supported at the be- eye to make himself weep. that was ginning by the Rockefeller Foundation and contain quite a lot of lvsozyme, so never crvs- then by the Medical Research Council. Real- the source of his material but it ly, it was the enthusiasm of Kcilin and tallized. Watson came Bragg which persuaded the Medical Re- The next thing was that Jim people search Council to take us on. By the way, I to our lab. Ile too came as many work with me think Bragg was the only crystallographer know. He came to the lab to get on with in Cambridge, and probably the only crys- on proteins but he did not really piece of tallographer anywhere, who thought it was proteins. Fie brought a very exciting DN A was the possible to determine the three dimensional news to our lab which was that proteins. 'This structure of a molecule as complicated as a genetic material, and not in the States a protein. I remember myself when I came work had been demonstrated work was not back to Cambridge after the war. I did a PhD year or two earlier, but the certainly totally late because I had been away in the war and generally known and was even to Francis Crick. my research supervisor was not Max, it was unknown to any of us, 'ro SIR.IUIL\ ( AL \I)RLIt

So that is how Francis Crick got converted Well, it so happened that in Cambridge from proteins to DNA and of course was at this time, not in the Cavendish but in joined by Watson, who thought it would be what was then known as the Mathematical less hard work than working with proteins. laboratory, there was the first working elec- But I am notgoingany further with DNA, af- tronic computer in England. It was called ter all this is not my topic today. Ersatz Mark I and it was home-made, using On the protein site, we benefited very old fashioned semionic belts which the di- greatly from being in the Cavendish Labo- rector had brought up from the army. They ratory, which was in the physics depart- were ex-army belts from the war. It had a ment and therefore had very extensive total store of 512 words and I remember the workshops. Really everything in the devel- great day when they doubled it and we got opment of protein crystallography de- 1024 words. Of course it was by normal pended on new methods and new tech- standards extremely slow. Well, of course, niques. Apart from the X-ray cameras we the PC I have on my desk at home has a used, everything was home-made, starting store of 450 megabites and it is much much with the X-ray tubes. Conventional X-ray faster, but this was the first working elec- tubes were not powerful enough. Protein tronic computer which you could program crystals are at least half water and therefore to solve your own problems. Two of us give very weak diffraction patterns. So we working with a graduate student in Max's had to develop very powerful X-ray tubes. lab developed a programme which could On that thing the first rotating anode X-ray calculate for a synthesis which you need tube which really worked was developed in for doing the calculations for protein struc- the Cavendish laboratories. tu re. Then, measuring up the spots on the pic- You see, it is interesting that this compu- ture. It all began with an accident through a ter came on stream, just about the time discovery of my own. I was visiting King's when we were getting some results, and 1 College in London one day. There was a cell am perfectly sure if this computer had only biologist there who was very ingenious arrived ten years later, the structures would with his hands and had made with his own not have come out until ten years later. So hands a home-made equipment: a densito- that was a happy accident, if it was an acci- meter for measuring the optical density of dent. I think it was, but some people may thin sections of cells. I was watching him think our own providence was at work. doing this work and suddenly it occurred to Well, of course, the whole thing became me we might be able to use this machine for possible because of a proposal made by Ber- measuring the optical density of spots on an nal himself before the war. He maintained X-ray film and that was how densitometry correspondence with Dorothy Hodgkin, began. You see, it was clear that even if you who was working on a molecule which had could solve the structure, the amount of a zinc atom in it. He suggested to Dorothy computing you would have to do would be that if they could substitute a cadmium not only difficult but impossible to do by atom for the zinc atom, that might slightly manual methods or using those old-fash- change the spots in the X-ray pattern and ioned machines where you turn a handle. then you could determine the basis of the re- 'T'here was just too much of it. Mistakes flections as well as their intensities, and then would occur and it just would have never the problem would be soluble. been possible to work them through. Well, it turned out that for technical rea- PROTEiyREs1RCHI,N('.4M8R/DGEINTill.l'(L1TIilk IL Ilt.1 O

the structure as part of one PhD pro- sons Dorothy could not use the scheme. Af- solve In the meantime, the Medical Research ter the war Max Perutz and his collaborator, ject. thought our laboratory required its Ingram, got it to work with haemoglobin. Council building, and we persuaded Fred San- Shortly afterwards, we got it to work with own come to biochemistry and Sydney myoglobin. That was when the whole thing ger to from South Africa and Aaron Klug began to come out and, in fact , the results of Brenner came to join us. Aaron Klug himself won a my own protein. The first picture of it was prize and he is now President of our obtained at low resolution in 1957 and at Nobel Society. high resolution, that showing all the atoms Royal course, another thing that has hap- separately, was in 1959. A little bit later, Of that this useless subject - molecular Max Perutz got haemoglobin out too. His pened is has become very important in the protein, being four times as big, took longer. biology- world. When I say useless I do not re- Of course one person who was very pleased wider anybody in our lab thinking or sug- with this was Linus Pauling, because Linus member knowing the structure of pro- Pauling had shortly before proposed the gesting that could ever be important except as a (i-helix as a structural component of pro- teins pure knowledge. However, that teins. Of course the a-helix had never been piece of of a protein structure together observed, so it was a purely theoretical pro- knowledge knowledge of the structure of the posal, but once we got the high resolution with the now become the foundation of picture of myoglobin we could see the a-he- DNA has very important new industry of bio- lix in there . Linus Pauling was very pleased this So useless subjects often do be- to see this but rather wished that he got to technology. later . That reminds me, by the solve the structure of proteins himself, just come useful of Bragg's very distinguished as he wished to solve the structure of DNA way, one Cavendish Laboratory was which, as you probably know, he failed to critics in the It was at the time when J. J. do because he went for a structure with Rutherford. discovered the electron and three chained helixs but the real structure Thomson had had discovered the neutron and has only two chains. Chadwick was well established. Ruther- That is really the story and I tell it briefly. the Bohr atom interviewed by a press man who Of course, since then protein crystallo- ford was if that work would ever be use- graphy has become a major activity world- asked him said: Of course Hot, it is just a piece wide. I mean, we took for operating work ful, and he knowledge! ten years. When I remember back on it, it is ofpure years after that came some really an amazing thing that the Medical Re- Only five some very had things, nuclear en- search Council kept this going for ten years. good and out as well as the atomic bomb. They never refused giving us money. We gines came things do come out, non practi- were never assessed and we had no results! So, practical Indeed, I think now that the pen- The only papers we published were ones cal science. swang too far in the direction of which later were shown to be quite inco- dulum has science. I do not know what is like rrect. So it was really a kind of golden age applied Spain but certainly in nw country for basic experimental science. I cannot ima- here in money goes into applied science gine this happening today. Of course, now most of the course, a lot of it is handled by in- the whole business in solving protein struc- and, of Well, it is very important because, tures has become much more rapid, so that dustry. in England we were not good at the research of a graduate student can often certainly , _"() .)7R JU/I \ ( K! \7)RI O

applying science and industry; we did not modern times. I think the activities on pro- do it properly. But I think the pendulum has tein research today are well known, but a lot now swung too far and really basic science of it did begin in Cambridge, and I must say -what I call useless science: learning know- I was myself extremely fortunate to have ledge for its own sake- is being very badly been in Cambridge at the time all this starved hap- for money, not only in England, but pened. in many other countries. The fact is that you Like Rutherford, we cannot predict the could never have applied this new field, future. Another example of this: I remember biothecnology. It could not have existed a refugee, Professor Frish, who was invol- without this useless research on the structu- ved in the discovery of nuclear fission, came re of proteins and the structure of DNA in to Cambridge and worked in the Caven- the 1950's. You got to have good basic scien- dish. Few years after the war he was giving ce in order to get good applications. We a lecture which I attended about nuclear keep telling this to the politicians but they physics and somebody put his hand up on never listen. his back and said: Professor Frish, what's By the way, molecular biology has of going to happen next in nuclear physics? and he course changed too, because at the time I am simply said: If I knew that I would be doing it!. speaking of it was sort of a subject to do with Well, we none of us know what is going to proteins. Nowadays people rather forget happen and really none know how it all will the proteins and they think it is all molecu- finish. I think, in fact, science is unpredicta- lar genetics and cloning and they think of ble. This is exactly what makes it the most DNA but forget proteins, but of course it is exciting activity in the world. So, thank you really both. Well, that really brings me up to very much.