The first time I met Prof. Dr. Herman J.C. Berendsen was when I took his undergraduate physical chemistry course, required for chemistry majors at the University of Groningen. I found him to be very likable, but also a bit intimidating. At the time a respectful distance was maintained between professor and student. Later it became the norm to call professors by their first name and use the familiar pronoun jij/je instead of the formal U. Herman encouraged this informality and, somewhat reluctantly at first, I adapted to the times. Herman was obviously a man of extreme intelligence. Later, when doing my dissertation research in his lab, I found out that he was also a highly creative man with a broad range of interests. Herman clearly had unique qualities, but this did not isolate him. He was very approachable and made an effort to put you at ease. After taking a special topics course with him in biological spectroscopy, I decided that I wanted to specialize in biophysical chemistry, Herman’s division within the physical chemistry department.

Herman’s teaching style was profound and playful at the same time. I remember his explanation of diffusion using drunken sailors swerving from one lantern pole to the next. Eventually they will come to the end of the street. In his physical chemistry notes for biology students there is a beautiful derivation of the expression for entropy, using a simple numerical example. I have used it many times in my own teaching.

After obtaining my M.Sc. degree in 1975, I went to Leeds in the UK to learn solid state pulsed NMR techniques to study liquid crystals. Herman expressed an interest in this new approach to solid state NMR, and I stayed in touch with him. So when, after a year and a half in Leeds, a position opened up in his lab for a graduate student, I jumped at the opportunity and returned to Groningen. At that time Herman was already shifting his focus towards Molecular Dynamics, away from experimental spectroscopy. Still, typical of Herman, he stayed interested in new developments in a broad area of science. Therefore he gave me a chance to prove myself, and I have been forever in his debt.

At first my research in Groningen was bumpy. There were equipment problems and difficulties with the necessary organic synthesis. Herman maintained his support throughout and obtained the resources to solve these problems. Finally it all came together and on May 1, 1981 I obtained my Ph.D.

Herman was, apart from being a great mentor, a good psychologist as well. He felt that a dissertation should be mainly the work of the student, and I totally agreed with him on this. He did not micromanage, but knew when to jump in and give a little nudge in the right direction. When you discussed your work with him you had to be well prepared, because his time was precious. The sessions we had could easily take a whole afternoon. At the end of those intense discussions we were both exhausted. He gave it his all.

After graduation I moved to the US, where I was going to specialize in biomedical applications of NMR. Because our interests diverged I gradually lost contact with Herman. Once in a while I googled him to see what he was doing. It was good to see that he remained active and very productive. The last time I looked him up on the internet, I found out that he had passed away. That news put me off balance for a long time. My scientific father gone! Over time I came to realize how lucky I have been to have known Herman and to have benefitted from his exceptional gifts.

When Larry Berliner, editor of The Protein Journal, asked me to be guest-editor for a Herman Berendsen Special Issue, I felt that here was a chance to repay Herman a little bit for everything he had done for me. It has been a rewarding experience, especially reconnecting with many colleagues, classmates, and friends from around fifty years ago. It was a little bit like a reunion of Biophysical Chemistry at Groningen in the seventies. I am grateful to all of those who are sharing their personal memories of Herman in this Special Issue. I am sure that their contributions will be read with much interest and pleasure. Now retired, my career has come full circle. It started with Herman and now it ends with him.

Jan F. Post, Ph.D.

Guest-Editor