Biophysical Society Bulletin | January 2023

Biophysicist in Profile

Antonio Alcaraz Areas of Research

Institution University Jaume I

Applied physics, molecular biophysics, electrochemistry, physical chemistry, transport phenomena in membranes, membrane proteins, and ion channels

At-a-Glance

Antonio Alcaraz grew up in Castell ό n, Spain, a small city by the Mediterranean Sea, and is now a professor at the city’s University Jaume I. “I am fascinated by biophysics,” he shares, “because of the enormous diversity of physical problems that it involves both from the theoretical and experimental point of view. Trying to understand the function of membrane proteins involves knowledge of fluid mechanics, electrostatics, thermodynamics, statistical physics, electronics, electrochemistry, phys ical chemistry, etc., while all this happens on a spatial scale in which traditional continuum theoret ical models are challenged by the molecular nature of matter and it is necessary to use molecular simulation tools.”

Antonio Alcaraz

Antonio Alcaraz , full professor in the Department of Physics at University Jaume I (UJI) in Castell ό n, Spain, grew up in the same city. “Castell ό n is a small city located in the east of the Iberian Peninsula, by the Mediterranean Sea. It is a beautiful place because the mountains are very close to the sea and one can find different landscapes in short distances. Also important, the weather is not extreme in either summer or winter,” he says. “Although Castellón lacks some of the advantages of large cities, the place is quiet and relatively well connected to Valencia, Barcelona, and Madrid.” No one in his family was involved in science but his father, a lawyer, and mother, who did administrative work in the Police Traffic De partment, instilled in Alcaraz and his sisters a love of reading, studying, and enjoying culture. In high school, he was interested in science, English language, history, economics, and philosophy. “During my last year I met some friends that were studying for a degree in physics. I was attracted by the combination of mathematical principles with physical concepts that can be probed with experiments,” Alcaraz explains. “This feeling was intensified when biophys ics came into play. Biological systems are amazing in terms of diversity and complexity. Trying to explain biological functions in terms of physicochemical molecular mechanisms is an extraordinarily challenging task.” Alcaraz attended the historical University of Valencia to study physics as an undergraduate. “Interestingly, higher education was established in the city of Valencia in the 13th century thanks to King James I of Aragon. However, it was not until October 30, 1499 that the Juries of Valencia drew up the Con stitutions of what would become the first University of Valen cia,” he reports. His specialization was in fundamental physics (physics at or below the atomic scale), but he especially liked courses in thermodynamics and statistical physics. “I obtained a scholarship to do my doctorate degree in Transport Pro cesses in Membranes in the Department of Thermodynamics,

under the supervision of Salvador Mafe and Patricio Ramírez ,” he explains. “I really enjoyed working with them. We got nice theoretical models of impedance spectroscopy in ion-ex change membranes that we confronted with experiments done at the University of the Saarland in Germany, where I stayed several months doing a research stay. We reported the results in a series of publications, and I got the PhD Research Award of the University of Valencia.” Following the completion of his PhD program, he was hired by UJI as a teaching assistant. To obtain a tenure-track position, he was required to undertake postdoctoral research at other institutions. “First, I did a postdoctoral stay of several months at the University of Twente in the Netherlands, working on topics like those of my thesis (industrial separation processes, electrochemistry, water desalination) in the framework of a European Union Thematic Network,” he shares. At UJI, he met Vicente Aguilella , who was working in membrane transport dealing with biological systems. “That was the first time that I heard the term ‘biological ion channels’ in relation to the use of ‘membrane pores.’ Vicente suggested to me that my background in membrane electrochemistry could be useful to learn ion channel electrophysiology in the laboratory of one of his collaborators, Sergey Bezrukov , at the National Institutes of Health (NIH). That stay, in 2001, widened my scientific perspective because I realized that biophysics was a fascinating world, both from the theoretical and experimental point of view,” he recalls. “From that time, I remember with special fondness the ‘chocolate seminars’ organized by Adrian Parsegian with extremely fruitful and passionate discussions with NIH staff and many visitors taking place. That stay of several months, and other similar ones in the following years, were like an open door to a new world and I will always be grateful to Vicente, Sergey, Adrian and all my other col leagues. The collaboration with Sergey’s group at NIH still goes on after more than 20 years.”

January 2023

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