IN Memorium

Professor Michael Bendikov

1971-2013

Professor Michael Bendikov 1971-2013

Michael Bendikov passed away on July 2, 2013 at the age of 41 after he finally succumbed to cancer after a truly heroic battle for eight years. During these years Michael never wavered in his quest to advance his scientific work, reaching new pinnacles in the field of “organic electronic” materials. Michael was a realist and an optimist in many ways and certainly so in his scientific life. In such a way he was remarkably efficient in putting aside the turmoil in his personal life and continued his professional career as if he was not ill at all. Going through major surgeries and exhausting chemotherapies, and faced with a highly pessimistic prognosis he maintained the level of activity and the positive attitude that gave outsiders no hints of the difficult struggle that he was going through. It was truly inspiring to those around him how he dealt with this adversity and he represented in his actions true courage. It is during these years that his scientific legacy was created. He lived his life with a passion and we are deeply saddened to have lost him as friend and colleague.

Michael was born in 1971 in Kharkov in eastern Ukraine. Already in high school he demonstrated his passion for science and chemistry and placed 1st in the Ukrainian Olympiad in Chemistry and 3rd in the Soviet Union All-Union Olympiad in Chemistry at the young age of 17. His began his education towards his chemistry degree at the Kharkov State University. His studies there coincided with the major geopolitical transformations in the USSR and as a result, in 1991 the Bendikov family immigrated into Israel. Living in Haifa, Michael was able to complete his BA in chemistry at the Technion in 1993. He immediately continued his studies under the tutelage of Prof. Itzhak Apeloig and obtained his M.Sc. (1996) and Ph.D. (2001) degrees carrying out research that focused on organosilicon compounds with unusual bonding. The combined experimental physical organic and computational chemistry background that he acquired during this time very much defined the way he has approached the chemical problems his independent career. Michael’s postdoctoral research with Prof. Fred Wudl at UCLA (2001–2004) was in a different field of synthetic materials chemistry, with emphasis in polymeric materials and introduced to organic electronic materials.

In 2004 Michael joined our department as a senior scientist and built his independent research group. The organic/material chemistry program of the 'Bendikov' group focused on the general field of advanced materials, with a particular focus in the areas of conductive polymers and novel organic electronic materials. They combined synthetic chemistry with materials characterization and computational chemistry to comprehensively study the field of organic electronic materials using physical organic chemistry tools. Two research directions of greatest current importance in this field are the design and synthesis of new materials and improving understanding of the properties of existing materials. Some of the most important contributions were.

Highly conductive, electrochemically active and very stable polyselenophenes are a new class of polymers prepared by a general and efficient synthetic strategy by Michael’s group. The importance of this advance was recognized by JACS through is re-publication of the original research in a second “JACS Select” issue. Noticing that one of the basic problems in conjugated polymers is that even small substituents on their conjugated backbone cause significant twist, reduced conjugation and higher band gaps, Michael showed that oligo- and polyselenophenes are more rigid than their thiophene analogues and can maintain their planarity and low band gap with substituents. The research in this area has also evolved into the study of polyselenophenes as superior, in fact best, electrochromic materials ever reported. Taking advantage of the lower bandgap of polyselenophenes, a new family of low bandgap conducting polymers, based on seleno[3,4-b]selenophenes, includes members with a very low bandgap. DFT computational studies supplemented the experimental research towards the understanding of the properties of these new polyselenophenes.

However, it seems to me that the crowning achievement of Michael’s group was probably the first synthesis of oligofurans, compounds that many thought could not be made. His research in this area was just beginning but immediately upon his initial reports may other research groups picked up on this finding.

A key feature in Michael’s approach was the focus on a fundamental understanding of structure-properties relationships, most significantly in establishing the role of heteroatoms in the properties of polymeric chains. Combining experimental and computational research, Michael showed that replacing sulfur with oxygen also increased the rigidity of conjugated chains, making them more resistive to twisting. He showed that this property led to their unique applicability in organic electronic materials.

The result of this research is over 80 top quality publications, for which he received worldwide recognition by receiving the DuPont Young Professor Award (2007), the France Israel Foundation Award for Academic Excellence (2009), the Israel Chemical Society Outstanding Young Scientist Prize (2009), the Weizmann Institute Scientific Council Prize for Chemistry (2010) and the Journal of Physical Organic Chemistry Award for Early Excellence (2010). It sad to see that this research will not continue here, but we are certain that Michael’s research will lead to further studies by others. It will be the legacy of Michael’s life and scientific contribution. Perhaps this will put a small smile on the faces and relieve some of the pain of his wife, Tatyana, who stood by his side and always believed in him and his children, Rosie and Batya, and the rest of the Bendikov family.

Written by Ronny Neumann

Professor Joseph (Yossi) Sperling

1939-2013

Professor Joseph (Yossi) Sperling, Weizmann Institute of Science, The Hilda Pomeraniec Professorial Chair of Organic Chemistry, passed away suddenly and unexpectedly on 19.1.2013, and we all miss him badly. Yossi was an original and innovative scientist who combined his interdisciplinary expertise in Chemistry, Organic Chemistry, Photochemistry and Molecular Biology to elucidate key questions in Biology and Chemistry. He was also an excellent teacher and supervisor and mentored several generations of students, many of which reached senior positions in academia and the biotech industry.

Professor Joseph (Yossi) Sperling 1939-2013

Yossi was born in Tel Aviv. He received his BSc in Chemistry and Physics at The Hebrew University of Jerusalem, and his MSc in Organic Chemistry, under the supervision of AD Bergman, at the Hebrew University of Jerusalem. During that time he worked at one of the first Israeli hi-tech companies, specializing in synthetic Organic Chemistry. He then continued his PhD studies at the Department of Organic Chemistry, at The Weizmann Institute with Prof Dov Elad, specializing in photochemistry of small molecules and peptides. His Postdoctoral fellowship at the MRC Laboratory of Molecular Biology, Cambridge England, with Brian Hartley, helped him combine his Chemistry expertise with Molecular Biology.

In 1973 he returned to Israel to The Department of Organic Chemistry at the Weizmann Institute where he worked to his last day. He started his own research by combining his expertise in photochemistry with molecular biology to understand structure-function relations in complexes of proteins and nucleic acids. He pioneered the use of photochemistry to decipher protein nucleic acids interactions in biological complexes, studies that were quoted as “bench Marks” in the field. Nowadays, the field of photochemical crosslinking of proteins and nucleic acids is at the basis of extremely high number of cutting-edge methodologies in biology. In parallel, photochemistry was used to elucidate how the internal interaction (stacking) of nucleic acid bases in DNA and RNA selectively protects them against photochemical reactions (damage). The concept was taken a step further to bacteria in which a new endonuclease specific for photochemical induced modification of purines was discovered.

After a Sabbatical at Stanford he started working on splicing and pre-mRNA processing, combining chemistry, molecular biology and structural biology to study the structure function relations of the splicing machine in collaboration with Ruth Sperling of the Hebrew University. Splicing and alternative splicing are key regulatory mechanisms and major factors in generating the diversity of the human proteome. Aberrations in splicing may interfere with normal cell growth and development, and thereby partially explain the development of certain cancer cells. In his studies of pre-mRNA splicing, Yossi was the first to isolate, visualize and characterize the cellular machine that splices together the genetic information encoded in the DNA – the supraspliceosome. The entire repertoire of nuclear pre-mRNAs, independent of their length or the number of introns they contain, are found assembled in splicing-active supraspliceosomes. Yossi and his colleagues have produced the most detailed three-dimensional structure of the supraspliceosome to date and clarified numerous important aspects of its function. He showed that the supraspliceosome is the in vivo pre-mRNA processing machine. It is a multiprocessor machine within which splicing, alternative splicing and all nuclear pre-mRNA processing activities are regulated (e.g. 5’ and 3’ end processing, RNA editing and biogenesis of intronic miRNAs). Furthermore, he discovered a quality control mechanism that operates within the supraspliceosome termed suppression of Splicing (SOS) that is required to ensure the production of translatable mRNA. Importantly, he showed that when this mechanism is abrogated (e.g. under stress or in cancer) thousands of defective transcripts are expressed.

Yossi pioneered gold nanocluster chemistry, first, to enable electron microscopy visualization and localization of RNA and proteins within the supraspliceosome, a method with general applications for protein-nucleic acids complexes. These studies led to his collaboration with Prof. Israel Bar-Joseph of the Weizmann Institute to study electronic transport and optics with nanoparticles assemblies. This collaborative work addressed a major challenge in realizing a functioning single molecule transport device: finding a reliable and well-defined method to contact the molecule. By forming constructs, comprise of a single molecule directly connected to two gold nanoparticles (dimer), the transport properties of several conjugated organic molecules could be measured. Furthermore, the strong amplification of the electromagnetic field in these dimeric constructs made this system useful in studying various plasmonic effects. Raman spectroscopy of single organic molecule was demonstrated, and the plasmon-exciton interaction in semiconductor quantum dots was investigated.

Yossi was a pioneering, original, and innovative scientist. He was problem oriented, and combined his interdisciplinary expertise in Chemistry, Organic Chemistry, Photochemistry and Molecular Biology to decipher key questions in biology and chemistry. Yossi pioneered the use of photochemistry to decipher protein nucleic acids interactions in biological complexes, studies that were “bench Marks” in the field. Together with colleagues he discovered the supraspliceosome – the in vivo pre-mRNA processing machine - and have produced the most detailed three-dimensional structure of the supraspliceosome to date. He clarified numerous important aspects of supraspliceosome function as a multiprocessing machine, including the discovery of a novel quality control mechanism as part of the supraspliceosome, which is abrogated under stress and in cancer. In parallel, Yossi pioneered gold-nanocluster chemistry, both for EM localization of protein and nucleic acids in biological complexes, and for introducing gold-nanoclusters as a reliable and well-defined method for electronic transport and optics measurements at the nanometric scale. Yossi was an excellent teacher and supervisor and gladly shared his expertise with students and colleagues. He taught and mentored many graduate students and succeeded to see several of them reaching senior positions in Academia and the Bio-Tech Industry in Israel and abroad.

Written by Avi Minsky

Professor Abraham Patchornik

1926-2014

Prof. Abraham Patchornik (Patcho) passed away at the age of 88, in his hometown of Ness Ziona. He was a brilliant chemist, who enjoyed an international reputation as a leader in the fields of bioorganic chemistry and photochemistry, as well as being an innovator in the use of functional polymers as chemical reagents. Abraham was born in Ness Ziona, the great-grandson of Reuben Lehrer (a.k.a. Reuven Zangvil Patchornik), who in 1883 became a legend when he purchased and built, the settlement of “Nachalat Reuven” in Wadi Hanin, a settlement that went on to become the town of Ness Ziona.

Professor Abraham Patchornik 1926-2014

Prof. Abraham Patchornik (Patcho) passed away at the age of 88, in his hometown of Ness Ziona.

He was a brilliant chemist, who enjoyed an international reputation as a leader in the fields of bioorganic chemistry and photochemistry, as well as being an innovator in the use of functional polymers as chemical reagents.
Abraham was born in Ness Ziona, the great-grandson of Reuben Lehrer (a.k.a. Reuven Zangvil Patchornik), who in 1883 became a legend when he purchased and built, the settlement of “Nachalat Reuven” in Wadi Hanin, a settlement that went on to become the town of Ness Ziona.

As a member of a family that was primarily involved in various branches of agriculture, Abraham started out as a young worker on the family farm—the accepted and expected path at that time. At a young age he was already asking questions and investigating his environment, arriving at early solutions to typical problems on the farm. It was here that he realized his love of science in general and of chemistry in particular. There was no high school at that time in Ness Ziona, so he was forced to travel to the “Gymnasia Re’alit” in Rishon LeZion—a long distance in those days. When he began studying chemistry, he set up a small laboratory for himself at home where he could conduct his many experiments undisturbed. His path to studying chemistry at the Hebrew University was not an easy one; the Gymnasia he had graduated from was not recognized by the Department of Education of the Jewish National Council (this was before the establishment of the State of Israel), and Abraham had to take the “external” Bagrut examinations—all this in parallel with his work in the family farm.

The Patchornik family did not look favorably upon Abraham’s plan to study in university rather than assume his place on the family farm (orchards, honey bee breeding and other branches of agriculture), as was customary in Ness Ziona in those days. The only encouraging and supportive voice was that of his mother, and he enrolled in University with her blessing. At first he wasn’t accepted to study chemistry and was directed to study mathematics and physics; it was only at the end of his first year that he realized his dream to study chemistry at the Mt. Scopus campus of the Hebrew University. All studies were cancelled with the outbreak of the War of Independence, and Abraham was drafted into the IDF. As a student of chemistry, he was assigned to the Engineering Corps; he was injured in the battle of Latrun, and fought in the Galilee. At the end of the war, with the disconnection of Mt. Scopus campus from Jerusalem, he completed his chemistry studies in university classrooms and laboratories scattered throughout West Jerusalem.

In 1952 Abraham began his doctoral studies under the mentorship of Prof. Ephraim Katchalski (soon to be Katzir) in the Biophysics department of the Weizmann Institute of Science, and his thesis title was “Polyamino Acids as a Model for Proteins”. He completed his doctorate in 1956. That same year he traveled to the United States to pursue post-doctoral studies at the National Institutes of Health (NIH). In 1958 he returned to Israel and joined the scientific staff of the Department of Biophysics at Weizmann.

Abraham led and developed many areas of research in chemistry, and became a leading world figure in the chemistry of peptides, supra-molecular chemistry, chemistry using insoluble functional polymers, bioorganic chemistry, photochemistry and analytic chemistry. His findings were published in more than 200 scientific publications.

Abraham was a “Shomer Masoret” (traditionalist) and named many of his findings, methodologies or chemical reactions, after parables, customs or events connected to Jewish tradition. What follows is a sampling of the varied chemical reactions he developed, together with the names he chose to assign to them:

Abraham and his group in the Biophysics department developed new chemical procedures for selected cleavages of protein chains at defined amino acids – tryptophan, cysteine, serine, histidine, phenylalanine, proline and hydroxyproline, methionine, and glutamic acid. He named them “Protein circumcisers”.
Patcho was among the first in the world to develop uses for insoluble functional polymers in unique chemical reactions for the preparation of fine chemicals in laboratory and industrial scale quantities, at very high yields and at particularly high levels of purity. Among others, these innovations included the following:
“Matchmaker Chemistry”: A process by which two different molecules, A - the “groom” and B - the “bride”, are connected to two insoluble polymeric carriers located in separate containers. Molecule C -functions as the soluble “matchmaker”—removing the “bride” molecule from its carrier and transferring it in solution to the polymer-bound “groom” molecule, thus creating the desired soluble molecule A-B.
“The Wolf and the Lamb Reaction”: In this system two chemically reactive molecules (one the “wolf” and one the “lamb”) are bound to two separate insoluble carriers, thus preventing any spontaneous chemical reaction between them (the “wolf” cannot attack the “lamb”). By rational use of soluble reactants it is possible to prepare and isolate final and intermediate products, which are usually unstable in a system where all the components are in a mixed solution.
Bioorganic Photochemistry was an area of research that Abraham pursued from the beginning of his early days at Weizmann until after his retirement. He prepared photosensitive organic molecules to selectively protect functional groups or specific sites in proteins or other polymers. When the protective agents completed their job, it was possible to remove them under very mild conditions by photo radiation, using visible light. This method was used in the synthesis of peptides and other bioorganic molecules in solution.
Another use for this type of chemical reaction was named “Enzyme Resurrection”. In this method he demonstrated the inactivation of an enzyme by blocking its active site using photosensitive inhibitors, and at the end of the process inhibition could be reversed using photo radiation—thereby “resurrecting” the enzyme.
“Biological Chips”: Abraham demonstrated that it was possible to use photosensitive chemicals to mask solid surfaces, such as polymers, glass and metals, selectively and reversibly. Today, this technique is the most widely used, and useful, of all of his discoveries in photochemistry. It is used in the preparation of various types of chemical or biological chips, in which solid surfaces are coated with thousands of different molecules. Among other things, these biochips enable the simultaneous analysis of thousands of biological reactions. Their primary importance is in research and diagnostics.
Quantitative Analytical Chemistry is another area of interest Abraham integrated with all his other research topics. He ascribed great importance to quantitative determination, at any given time, of all the components of the systems his research group was working on. Thus, in parallel to whatever research projects were being conducted by the group, he developed methods for quantitative analysis of all the components of those systems—in a mixture, without the need for isolating the individual component under examination.

The common denominator of all his analytical methods was their simplicity and high reliability.
Abraham was not given to taking pride or resting on the laurels of his many scientific achievements, with the possible exception of what he called, with great affection, “My Chanukiah”. The nine candles in his candelabra symbolized the nine students he mentored who went on to become professors in Israel (seven of them at the Institute): Shmuel Shaltiel z”l, Mordechai Sokolovsky, Meir Wilchek, Mati Fridkin, Yigal Burstein, Marian Gorecki, Menachem Rubenstein, Yoram Schechter, and Yehiel Shai. Many of his other students entered fields of industry, and made their mark in senior positions in project initiatives, administration, research and development.

Abraham was devoted not only to his students, but also to other students in the department; he especially enjoyed the humorous pranks that were common amongst them. Some of the top scientists in the country, who as students led these mischiefs, owe him the “last chance” they were granted to complete their studies at the Feinberg Graduate School of the Weizmann Institute.
Scientific research was always Abraham’s primary interest but, unlike most of his colleagues in the Institute, it did not prevent him from promoting potential applications of his research results. Upon joining the Department of Biophysics, he proposed establishing a “company” for the commercial production of fine biochemicals based on knowledge gained in the department. Professors Ephraim Katzir, Michael Sela and Arye Berger joined this initiative. During the first year, Abraham served as scientist, administrator and marketing salesman for the new company. In 1960, with the establishment of “Yeda”, the commercial arm of the Weizmann Institute, this job was passed on to them. In time the company was sold to “Miles”, and eventually to “Sigma”. Throughout his career Abraham continued in his efforts to promote applied aspects of his research, and over 40 patents are registered in his name.

From 1970-1973 Abraham served as the first chief scientist of the Ministry of Development. In 1972 Abraham was appointed Head of the Department of Organic Chemistry at the Weizmann Institute, and filled this role for seven years. From 1987, and for the next twenty years, he served as an advisor to Ministers of the Israel Police and to the Police Forensic Department. In 1988 he was awarded the Rothschild Prize in Chemical Sciences. When he retired he established the PCJ Chemicals Company for fine chemicals, where he continued to develop his ideas.

Alongside his work in this company, he focused on research into the history of Ness Ziona, as well as its preservation for future generations, at the “Beit Harishonim” in his town. In a similar vein, he led a series of get-togethers of “The Storytellers”, in which Institute veterans reminisced about “the old days” of The Daniel Sieff Research Institute and The Weizmann Institute of Science.
Abraham was an opinionated scientist, but also pleasant-mannered and always smiling and happy, direct but never blunt. Like a pomegranate, he sprouted a profusion of novel ideas, and it was necessary to learn to filter them all in order to be able to fully realize even some. Research projects that were already completed didn’t interest him anymore, even if they were not yet published; he had already moved on to the next challenge.

In the past few years, bowing to his declining health, Abraham retired from all his activities.

Abraham’s image will remain engraved in our memories and in our hearts. His students and colleagues in the Institute, here in Israel as well as abroad, are pained by his loss and send sincere condolences to his wife Tzipa, to his children Nona, Shuki, Shahar and Guy, and to the entire Patchornik family.

Written by Yigal Burstein