PROFILE

Profile of Steve Granick PROFILE

Sandeep Ravindran, Science Writer

Steve Granick says a simple underlying principle—the Late Pivot to Natural desire for an interesting life with meaningful human Science relations—has guided his career. During undergradu- Granick dropped out of col- ate study at , Granick majored in lege after his junior year as an sociology, mainly because he was interested in litera- undergraduate at Princeton ture, humanities, and social sciences. He took just one University. “I bummed around obligatory science class—introductory —and the [United States] taking odd found it so dry that he never took another one. De- jobs for three years,” he says. spite his initial lack of interest in science, Granick “One of those jobs turned out would go on to have a distinguished scientific career, to be ... in an oil field,” says eventually becoming director of the Institute for Basic Granick. “They were desperate Science (IBS) Center for Soft and Living Matter in for workers, so you would show Ulsan, South Korea, as well as being elected to the up and you would see this National Academy of Sciences in 2015. lighted derrick in the distance at “To me, research is like traveling the world. Some night—they called it the Christ- people like to visit a different country every few years, mas tree—andifyouhadtwo and I feel that way about scientific problems,” said hands and two feet, they would Granick. Working across disciplines, Granick’s wide- hire you. That was my introduc- ranging interests have led him to address the chemis- tion to lab work, and it turns out try and physics of everyday life, especially complex Ienjoyedit.” fluids, colloids, polymers, lipids, thin films, and bioma- Granick enjoyed this peri- terials. “It’s all over the place,” Granick says. But he patetic phase so much that he Steve Granick. Image Courtesy of Steve also says there is a simple, unifying theme underlying became inspired to begin in- Granick. the research pursued in his interdisciplinary labora- tellectual wandering with a tory: “To understand everyday life.” similar spirit: he took some science classes. “As a “What ties it together is that the rules of complicated nondegree student, I took classes in a state where I systems with interactions are not so different in all those could do that inexpensively: Wisconsin,” he says. “I different systems, and also I love having coworkers who was intrigued, and decided to do some more,” says are curious about the world,” Granick says. Teaching and Granick. He completed the requirements for a bach- mentoring young scientists is central to Granick’swork.“I elor’s degree in sociology by correspondence, and enjoy seeing people live up to their potential,” he says. became a graduate student at the University “Sometimes you feel that, because they were encour- of Wisconsin. “By chance I found a great physical aged at a formative time in their lives, they take a new chemist, John Ferry, and he became my PhD advisor,” path, and then go forth and make contributions to the he says. “It’s not that I found his scientific problems world that might not have happened otherwise.” more interesting than others, but I thought to myself, Granick’s latest scientific endeavor, described in from this guy I could learn a lot,” says Granick. his Inaugural Article (1), resulted in a surprising discov- When he decided to pursue a postdoctoral posi- ery about how enzymes move, despite his laboratory tion, Granick wrote to Pierre-Gilles de Gennes at the never having worked on enzymes before. “Looking Collège de France, who would go on to win the Nobel back on it, nothing had changed,” says Granick. Prize in Physics 10 years later. “He turned out to be the “The actual world doesn’t know the difference be- right person at the right time,” says Granick. “He was a tween physics, chemistry, and social science; these maverick, known for discovering new fields of study to distinctions are artificial,” he says. “I turned a taste which physics could contribute.” Granick had studied for exploration into a career in science, finding ways polymers and macromolecules as a doctoral student, to avoid pigeonholing the lab’s research.” but under de Gennes’ influence he became interested

Published under the PNAS license. This is a Profile of a recently elected member of the National Academy of Sciences to accompany the member’s Inaugural Article on page 14 in issue 1 of volume 115.

www.pnas.org/cgi/doi/10.1073/pnas.1800048115 PNAS Early Edition | 1of3 Downloaded by guest on September 25, 2021 in studying surfaces and interfaces outside the high- and what are the mechanisms,” he says. For exam- vacuum environment in which they had traditionally ple, Granick and his colleagues used single-molecule been studied. fluorescence imaging to elucidate correlations be- Granick’s postdoctoral work led him to a fac- tween neighboring actin biofilaments and colloids ulty position at the University of Illinois at Urbana– rather than take the conventional mean-field ap- Champaignin1985.Bythetimeheretiredfromthe proach (7, 8). University of Illinois, Granick’s affiliations had ex- Granick avoids heavily populated fields. “Our work panded to include Professor of Materials Science naturally falls in the cracks between disciplines. This and Engineering, Professor of Physics and Bio- gives us tremendous freedom to do things at our own physics, Professor of Chemistry, and Professor of pace, without feeling like we’re competing to do to- Chemical and Biomolecular Engineering. “With day what someone might publish tomorrow,” says the passage of time my interests, which had been Granick. “I do my best to find, as coworkers, people so unorthodox ... became more accepted,” says who see the value of curiosity-driven research. There Granick. are too many others who look to cure cancer or solve the energy problem in the span of one postdoc or one Thinking Like a Molecule PhD thesis.” Interdisciplinary in character, Granick’s research has In 2014, after 30 years at the University of Illinois, led to discoveries in physics, materials science, engi- Granick became the founding director of the IBS neering, and chemistry. He works at the interface of Center for Soft and Living Matter, a blue-sky research these areas, especially as they apply to soft materials center that is part of the IBS in South Korea. “It’s and molecular interactions. “Every time I work on a the Korean version of a Max Planck Institute,” says new problem, I find I fall in love with it,” he says. Granick. “We invest in long-term research. Among “The goal of my lab’s research is to think like a scientists there’s great hunger for a place like this, molecule, to learn to second-guess what a molecule where you’re encouraged to follow your curiosity, would decide to do when confronted by external where you choose problems because you think they constraints in its complex environment,” says Granick. might make a difference rather than because you can “After we formulate the problem, measurements get a grant to support them,” he says. The multidis- made with an open mind lead to interesting sur- ciplinary approach that Granick enjoys at the IBS is prises.” Early in his career, this took the form of using exemplified by his Inaugural Article (1). the frequency dependence of linear viscoelasticity to study fundamental questions of friction and lubrica- Discovery About How Enzymes Move tion; Granick describes this work as foreshadowing Granick’s Inaugural Article (1) was the result of trying present-day interests in confined systems within and to resolve a mystery about how enzymes move. Re- outside of equilibrium physics. searchers elsewhere had discovered that enzymes “We found that when liquids are molecularly thin, appear to display enhanced diffusion when they cat- confined in one or more directions to the space of a alyze chemical reactions. “It didn’t make sense; how few molecules, they behave unlike any expected can diffusion change?” Granick wondered. macroscopic liquid, which raised many questions,” Granick was puzzling over these results when a says Granick (2). The advent of single-molecule tech- theorist colleague, Tsvi Tlusty, came to his office and niques broadened the scope of what was possible. He shared an unusual prediction. He suggested that the pioneered studies of polymer surface diffusion, water enzymes might be undergoing antichemotaxis, and hydrophobicity, and Janus colloids (3–5). Those that it should be observable. “I went to my postdoc, everyday-life questions and their sometimes-simple Ah-Young Jee, and tried to convince her that it was solutions have challenged the physics textbooks worth checking,” says Granick. “She went to a pro- when it comes to Brownian motion, framed new dis- fessor who is expert on microfluidics, and she hap- cussion around hydrophobicity, and created self- pened to have exactly the right kind of microfluidics assembling colloidal spheres that have the ability to that we needed,” he says. form useful self-assembled structures with collective “Within 48 hours, this postdoc actually got the behavior (4, 6, 7). Granick’s is a varied research port- preliminary result showing antichemotaxis, and we folio, which is just how he likes it. quantified this,” says Granick. “To me it encapsulates Granick sees the embrace of new technology as what we can do in this Korean setting that wouldn’t key to making scientific headway. “We can never be have been possible in most other places,” he says. as smart as the giants of the past, but the world of “We had the instrument, we had the theorist, we had technology has marched on, so we can measure the microfluidics person, we had the gifted postdoc, things they wouldn’t have imagined,” says Granick. and we had people willing to talk and listen to each Modern high-end optical methods enabled Granick to other. We didn’t have to write a proposal to try this,” look at individual molecules but with huge statistical says Granick. datasets to illuminate the influence of rare events. The researchers discovered that the motion of “With those instrumental capabilities, it became very enzymes was very much like the run and tumble of natural to look not just at interfaces, but also at bacteria. “I was flabbergasted at the results,” says bulk mobility, the dynamics of how molecules move Granick. “It may be relevant biologically. Because in a from point to point in space in crowded environments, nothing is distributed homogeneously, you could

2of3 | www.pnas.org/cgi/doi/10.1073/pnas.1800048115 Ravindran Downloaded by guest on September 25, 2021 imagine that this would have a tendency to homoge- much more sophisticated and complex than the field nize enzymes to be more likely to be where some of active matter has thought about previously,” he food is.” says. “It becomes very natural now to ask fundamen- “It’s connected to the field of active matter, which tally new, deep questions,” says Granick. is usually defined as the study of small objects that “The list of things to do is huge and it will occupy a move around by consuming some sort of fuel or en- lot of people, not just us,” says Granick. “There are so ergy,” Granick says. “These molecular systems are many things to do.”

1 Jee AY, Dutta S, Cho YK, Tlusty T, Granick S (2017) Enzyme leaps fuel antichemotaxis. Proc Natl Acad Sci USA 115:14–18. 2 Granick S (1999) in a tight spot. Phys Today 52:26–31. 3 Sukhishvili SA, et al. (2000) Materials science. Diffusion of a polymer ‘pancake’ Nature 406:146. 4 Zhang X, Zhu Y, Granick S (2002) Hydrophobicity at a Janus interface. Science 295:663–666. 5 Chen Q, Bae SC, Granick S (2011) Directed self-assembly of a colloidal kagome lattice. Nature 469:381–384. 6 Wang B, Kuo J, Bae SC, Granick S (2012) When Brownian diffusion is not Gaussian. Nat Mater 11:481–485. 7 Tsang B, Dell ZE, Jiang L, Schweizer KS, Granick S (2017) Dynamic cross-correlations between entangled biofilaments as they diffuse. Proc Natl Acad Sci USA 114:3322–3327. 8 Han M, Yan J, Granick S, Luijten E (2017) Effective temperature concept evaluated in an active colloid mixture. Proc Natl Acad Sci USA 114:7513–7518.

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