Zygmunt Wasylewski was born in June 13th 1942 in Chrzanów. He finished elementary school there and in 1956 he started learning at a Mechanical Technical School. One year later he continued his education at a Chemical Technical School in Chorzów, where he obtained a secondary school diploma.
In 1962–1968, he studied chemistry at the Faculty of Mathematics, Physics and Chemistry of the Jagiellonian University. He did his master's thesis under the supervision of Professor Włodzimierz Ostrowski in the Interdepartmental Chair of Physiological Chemistry at the then Krakow Medical Academy (now Collegium Medicum UJ). In this work, entitled "Determination of molecular parameters of phosphomonoesterase by molecular filtration", Zygmunt Wasylewski presented the values of effective Stokes radius, diffusion coefficient and molecular weight of phosphomonoesterase, determined experimentally. Then, for a year, Wasylewski worked as a scientific and technical assistant in the Department of Colloids, Faculty of Physical Chemistry, Mat-Physics-Chemistry Division, Jagiellonian University.
In 1969, he started work at the Department of Plant Physiology and Biochemistry of the newly established (1970) Institute of Molecular Biology at Jagiellonian University, directed by Professor Reifer. However, Professor Reifer’s research interests did not match those of the young master and in 1971 Z. Wasylewski moved to the Department of Animal Biochemistry of the same Institute, directed by Prof. Maria Sarnecka-Keller. Already two years later, Wasylewski defended his doctoral thesis entitled "Molecular Properties of various forms of acid phosphatases from liver and leukocytes", whose supervisor was Professor Aleksander Koj. In this work, using sophisticated chromatographic and electrophoretic techniques, as well as density gradient ultracentrifugation, Wasylewski, M.Sc., determined the degree of oligomerization of the molecules of the phosphatases studied and the geometry of the arrangement of protein subunits, and also demonstrated the structural similarity of acid phosphatases isolated from various tissues.
In his further research work, Dr. Wasylewski focused on interactions of model proteins with nonionic and ionic detergents, in particular with cationic detergents. In these studies he used a number of advanced physicochemical methods such as infrared spectroscopy techniques, Raman, EPR, hydrodynamic techniques such as gel filtration, ultracentrifugation and equilibrium dialysis. His independence and commitment resulted in an abundance of publications and a postdoctoral degree (habilitation) obtained in only six years (1979).
A new chapter in the scientific life of Dr. Wasylewski was opened by a one-year (1979/80) fellowship in San Antonio (Texas University), where he became interested in the application of fluorescence spectroscopy methods in the study of the structure, properties and dynamics of proteins. It should be emphasized that these methods allow for relatively easy study of proteins in aqueous solutions, thus being (besides NMR) a necessary complement to crystallographic methods.
Associate Professor Wasylewski (who received the title of associate professor in 1981) can be counted among the pioneers of the implementation of fluorimetric techniques in protein biochemistry. At that time, Wasylewski's "fluorescent" research focused on such enzymes as rhodanase, thiosulfate sulfotransferase, yeast hexokinase, alcohol dehydrogenase, metalloproteinase, phosphoglycerate kinase, human serine proteinase inhibitor and many other proteins containing two or more tryptophan residues. As a result of this work, in cooperation with Professor Horowitz, papers were published on temperature and ligand binding induced conformational changes of proteins in solution. Wasylewski's cooperation with Professor Efftink from the University of Mississippi (1986/87 for one year and in 1991 for three months as a visiting professor) was also conducive to further development in this field.
In 1986, docent Wasylewski and his research team developed a technique for decomposition of complex fluorescence emission spectra of multi-tryptophan proteins by fluorescence quenching-resolved-spectroscopy (FQRS). This technique is widely used today and has found its place in renowned textbooks on fluorescence spectroscopy.
In 1989, docent Wasylewski received the title of professor of biochemistry, and in 1991, the research group that had existed under his direction since the early 1980s (the Biopolymer Physicochemistry Laboratory within the Department of Animal Biochemistry) was transformed into the Department of Physical Biochemistry. The equipment base, still in Professor Wasylewski's laboratory at that time, was relatively rich, thanks to unparalleled constructional skills, persistence and enthusiasm of Professor Wasylewski, who designed devices, sought contractors for subassemblies of the designed apparatus far beyond the walls of the University, and then often screwed together and assembled individual elements with his own hands. It should be recalled that at that time there were almost no opportunities for the academic community to raise funds for the purchase of specialist equipment, but when the situation improved somewhat, i.e. around the middle of the 1990s, Professor Wasylewski immediately began his efforts to purchase high quality measuring equipment.
Initially, Professor Wasylewski's research interests were focused on the use of the FQRS method and other fluorescence techniques to study the molecular dynamics of proteins (e.g. parvalbumin, melittin) in solution, but also in model systems of biological membranes and in micelles. At that time, he investigated the mechanisms of fluorescence quenching, the red edge effect and the qualitative and quantitative analysis of fluorescence emission spectra. A little later, however, the main subject area of the Department of Physical Biochemistry crystallized. It concerned the influence of binding of functional ligands by bacterial regulatory proteins on the structure, dynamics and function of these proteins. Professor Wasylewski's research objects were proteins regulating transcription processes in E. coli, i.e.: tryptophan operon repressor (TrpR), tetracycline repressor (TetR) and cAMP-binding protein (CRP). Studies coordinated by Professor Wasylewski on the tryptophan repressor using a modified protein completely lacking tryptophan residues allowed to determine the nature of the L-tryptophan-locating microenvironment in the protein and also showed significant changes in the L-tryptophan-binding pocket area under the influence of binding of the TrpR-L-tryptophan complex to DNA. These studies used the FQRS technique, as well as steady-state and time-resolved tryptophan fluorescence emission measurements, and circular dichroism measurements. Parallel studies of the tetracycline repressor using the same measurement methods and protein mutants containing single tryptophan moieties enabled to understand the conformational dynamics of the protein domain responsible for interaction with DNA and to characterize the structural changes of TetR domains occurring as a result of protein interaction with tetracycline or operator DNA fragments. In turn, the application of the stopped-flow method with fluorescence detection allowed to characterize the kinetic mechanism of TetR protein interaction with DNA, as well as to describe kinetically the process of induction of expression of genes encoding resistance proteins under the influence of tetracycline binding, as well as to determine the role of magnesium ions in the induction process. The application of the isothermal calorimetric titration (ITC) method made it possible to understand the thermodynamics of the TetR-tetracycline interaction, while on the basis of data obtained by differential scanning calorimetry (DSC) a model of the TetR thermal denaturation process was proposed and the effect of tetracycline on protein stability was characterized.
The most extensive and probably the most valuable part of Professor Wasylewski's scientific output are works on CRP protein. The adventure with CRP began, one could say innocently, with the characterization of fluorescent properties of the protein. However, later, not easy kinetic studies using the stopped-flow technique made it possible to learn about the stability and kinetics of protein folding and unfolding, while the use of selective fluorescent labeling of cysteine residues made it possible to propose a detailed mechanism of chemical denaturation of CRP protein. The realization of Professor Warmus's ideas concerning further research on the function and structure of CRP protein required the introduction of many point mutations in "sensitive" areas of the protein. The realization of this last goal was as much a challenge as it was an appealing prospect. Thanks to Professor's steadfastness in pursuing his goal, a molecular biology laboratory was established within the Department of Physical Biochemistry, one of the first in the Institute of Molecular Biology, where, using the overlap extension PCR method, mutations were introduced and then verified by DNA sequencing. The intensity of research conducted on multiple mutants of CRP protein necessitated modification of bacterial culture and protein purification techniques. This resulted in the introduction of advanced affinity chromatography methods into laboratory procedures and automation of protein preparation, made possible by the use of a biofermenter and a specialized chromatographic system. The use of mutants allowed monitoring of ligand-induced allosteric changes in CRP, thanks to which the detailed kinetic mechanism of cAMP binding was described. In parallel, comprehensive structural studies (using DLS, FRET, fluorescence quenching, steady-state and time-resolved emission and fluorescence anisotropy measurements) were carried out to describe conformational changes in the protein induced by its interaction with cAMP and DNA. In turn, the thermodynamics of CRP-cAMP complex formation were studied using microcalorimetric methods (ITC, DSC). Since the crystallographic structure of the CRP protein not complexed with the ligand has not been known so far, there has been a discussion in the scientific community on the structural symmetry of the homodimer subunits. In the context of the arising research problem, a new unusual idea of Professor Wasylewski was born, concerning the construction of CRP protein heterodimer having only one tryptophan residue. The results of studies of cAMP binding kinetics monitored by energy transfer between the Trp residue and a fluorescent tag attached to a cysteine residue located in the same as Trp or in the second subunit of the protein showed the conformational symmetry of the CRP protein subunits.
The culmination of the CRP work was a project to investigate the interactions between elements of the entire E. coli transcriptional complex using selected promoter DNA fragments. This challenging project required the reconstitution of RNA polymerase from purified recombinant protein subunits. The formation of the transcription complex, which included a CRP-cAMP complex in addition to the RNA polymerase, was monitored by measuring the fluorescence anisotropy of fluorescently labeled DNA fragments. As a result, the effect of CRP on specific and nonspecific RNAP-DNA interactions was determined. Furthermore, the use of time-resolved fluorescence spectroscopy (FRET, fluorescence anisotropy) enabled the study of the conformational dynamics of transcription complexes.
Professor Wasylewski was fascinated by technical discoveries in the field of physical biochemistry and molecular engineering, with which the end of the 20th century was exploding. He not only followed them, updating his knowledge, but also used them practically as useful tools in his everyday work. Professor Wasylewski's talent as a designer, as well as his pragmatic personality, were once again evident when, entering completely new areas of research, he began to study the interactions between human neurotransmitter receptors in plasma membranes. The assumptions about their heterodimerization were confirmed experimentally for the first time thanks to him, and it should be emphasized that the competition in this field of science is enormous. The experiments consisted of measuring the fluorescence lifetimes of fluorescent proteins bound to receptors in a single living cell and required the use of sophisticated apparatus, which, however, could not be afforded. The need to answer this question was so urgent for Professor Wasalewski that he created a functional measuring system using components available in his laboratory.
The last year of Professor Wasylewski's life was dominated by the work on the formation of two completely new scientific projects. One of them concerned the human regulatory protein Ying-Yang1 and was a certain analogy and extension of the research conducted on the bacterial CRP protein. The other one concerned the application of genomics and proteomics methods to study the influence of antidepressant drugs on the protein profile of neuronal cells.This stage ended with a full success manifested by obtaining the financial support needed to carry out both of the intended tasks.
Professor Wasylewski was the principal investigator of four three-year research projects and is the author or co-author of about sixty scientific publications. In 1991 he was awarded the Knight's Cross of the Order of Polonia Restituta, and in 2002 he received the title of full professor. He was also a member of the Polish Biochemical Society, and from the early 1990s he was a member of the molecular biology, biochemistry and biophysics section of the Scientific Research Committee on several occasions.
Another very important aspect of Professor Wasylewski's professional activity was his didactic work. As an assistant, he conducted laboratory classes as part of a specialized biochemistry lab. Later, already as an assistant professor (1973), he also taught instrumental analysis in biochemistry. In 1980, Associate Professor Wasylewski began lectures in physical biochemistry, which were closely correlated with laboratory classes conducted by the staff of his Laboratory. After the formation of the Laboratory of Molecular Biology, in 1998, he introduced a course on protein engineering, which included both practical classes and lectures. The latter course in particular is of great interest to students as it comprehensively addresses the issue of obtaining protein mutants, starting from manipulation at the DNA level, through protein isolation, to determining its basic structural properties and checking its biological activity. With the introduction of biochemistry specialization in the Biotechnology faculty, two highly advanced courses were created: Physical Biochemistry II and Protein Engineering II. Professor Wasylewski was the supervisor of 13 doctoral theses and dozens of master's theses, he was also a reviewer of many scientific papers and research projects.
Professor Wasylewski was always kind to his students, he always had time for them and, what was rare, he bestowed a great deal of trust on the young people coming to the Department. He was able to attract students in many ways. In some of them, he aroused keen interest in the subject matter or methodology, in others he infected with scientific enthusiasm and in yet others he charmed with his openness and personal charm. One student, when asked by Professor Wasylewski what she would like to do in her Master thesis, replied: "I would like to clone Mozart", to which Professor replied: "That is what we are doing". This anecdote reveals one important quality of Professor Wasylewski: he was a visionary who set goals that for others could only remain in the realm of dreams and, without hesitation, strove to achieve them. He liked to surround himself with young people who were able to share his enthusiasm and optimism. Analyzing his scientific development, one can clearly see the evolution of the subject matter, which became more and more complex, but also more important, more interesting and, at the same time, more difficult.
Professor Wasylewski's professional life was inseparably intertwined with the life of the Institute of Molecular Biology (Faculty of Biology and natural Sciences, Jagiellonian University). In 1981–1984 he held the position of the Institute's Deputy Director for didactics, and in 1997–2003 he was the director of doctoral studies. He was a co-founder of the Faculty of Biotechnology and participated in the process of separation of the Faculty of Biotechnology from the Faculty of Biology and Natural Sciences UJ (2002). On several occasions, he made efforts to establish a major in Biochemistry, being deeply convinced of the need to strengthen the condition of his beloved discipline of science. These efforts unfortunately ended in failure and remained an unfulfilled dream of the Professor (it came true in the following years).
Professor Wasylewski was a man who had the good of his country at heart, as evidenced by his involvement in opposition activities during martial law (1981–1984) and later. He was one of the six members of the University's Secret Commission of Solidarity. This committee, composed of recommended members of the official Solidarity structure, was an expression of opposition of the academic community to the mistreatment they experienced from "people of the system". It operated from 1982 to 1988, and its main tasks were: breaking the monopoly of information of the "system" through the distribution of underground press, assistance to repressed scientists, as well as internal control of the university authorities by giving opinions on candidates for important positions. The activity of the Commission involved considerable risk, which its members were aware of, but their sense of duty to the University and their country, and above all their sense of dignity, made them take this risk. Interestingly, for some time the meetings of the Commission were held in Professor Wasylewski's apartment. Later, the Secret Intercollegiate Commission was established, in which Professor Wasylewski represented the Jagiellonian University. These important facts from the life of the University still await description, as do other, not always glorious, details from that difficult period, but – what sounds promising – has recently become the object of research by a special Senate Committee of the Jagiellonian University.
Professor Wasylewski was an extremely energetic man, eternally young in spirit but also very physically fit. Skiing was his passion and he was indeed an excellent skier, as participants in the Institute's annual winter schools could see for themselves. He was an exceptional man, combining seemingly contradictory features of a pragmatist and an idealist. Future-oriented, cheerful, family-oriented, and simply human, he passed away suddenly, in the prime of his life, leaving his colleagues and friends in grief.
Collected by: Sylwia Kędracka-Krok