Microbiology Professor Markus Aebi can relax in his office for a brief moment. His research group has again achieved a publication in “Science”. But that is not his primary concern on this occasion. He says modestly that “The knowledge we publish is something for specialists.” (1)

In this study the eight researchers involved in the Science paper discovered a novel concept about how and when N-glycosylation, i.e. bonding between sugars and proteins at particular amino-acid groups, occurs in bacteria. Aebi says this also helps to understand the processes in mammalian cells and makes a connection with humans.

A triviality with important consequences

In principle glycosylation in eukaryotes takes place in two stages. Initially a sugar is attached at a particular position on the protein and the protein then folds. In bacteria the protein folds first of all and enzymes then attach the sugar to it. As the ETH professor stresses, “That sounds trivial but it has important consequences.”

The multiplicity of glycoproteins in eukaryotes, i.e. in humans as well, is unbelievably large, whereas in bacteria only a few proteins are modified in this way. The reason is simple: in the bacterial system the opportunity to attach a sugar to proteins is small because of the protein folding that has occurred previously. The situation in eukaryotes is different. The glycosylation of proteins before their folding allows sugars to be attached at many different positions on the proteins. On the one hand this alters the folding properties of the proteins modified in this way, and on the other it also enables protein folding to be controlled via a standardised signalling molecule, namely this attached sugar.

This gives glycosylation an additional and vital function. Eukaryotic cells die because the glycosylation machinery operates incorrectly or not at all. Bacteria are not reliant on this process.

Glycosylation in vitro as well

It was only four years ago that a working group led by Markus Aebi discovered that bacteria are capable of glycosylating proteins at all. In the pathogen Campylobacter jejuni they found an unusual glycosylation system which they then incorporated into the “workhorse” of microbiologists and biotechnologists, Escherichia coli. Thereafter these bacteria were able to attach sugars to proteins. As a result of the new study, the scientists can now also show that this system operates in vitro.

This is interesting for pharmaceutical and biotechnology research because proteins modified with sugars are responsible for the effects in the case of the majority of proteins used in biotechnology and pharmaceutical applications. An artificial system can help in their preparation.

Three ingredients for a successful recipe

However, as already mentioned, for once Aebi’s primary consideration is not the paper but how and why such a study can come about. This is also seen in the light of the ongoing discussions about structure reform at ETH Zurich.

Shin Numao from Japan and the Australian Benjamin Schulz are members of Professor Markus Aebi’s multinational working group that has just published a paper in Science on N-glycosylation by bacteria. large

“Structures have only an indirect influence on our core business, which is teaching and research,” says the microbiologist. He also makes clear which factors are the more important: top-class colleagues, teamwork and interaction with other research groups. Aebi emphasises that “A paper of this kind could come into existence only through teamwork. “ An eight-person international team worked on the present study. Australians, Argentines, Belgians, Germans, Japanese and Swiss; all at the Institute for Microbiology of ETH; appointed as diploma students, doctoral students and post-docs. “I have a primary interest in recruiting well trained, motivated team members,” says Aebi.

These come both from within and from outside. For example first author Michael Kowarik studied at ETH, took his doctor’s degree with Professor Ari Helenius at the Institute for Biochemistry, completed his post-doc at the Institute for Microbiology and has now decided to pursue his career in industry. Aebi says that “Our commitment in teaching flows directly into the research, there is an inseparable connection.”

Successful learning and finance attract top-class people

But how can top-class people be recruited from outside ETH? After their stay at ETH, two of the co-authors, Mario Feldmann and Nico Callewaert, have become professors in Canada and Belgium respectively. The ETH professor is convinced that “They come to us only if they feel they will learn something more here.” However, he also makes no secret of the fact that an excellent infrastructure – the technical equipments at the Institute for Microbiology are state of the art – and adequate research funding attract top-class people from abroad. In fact Aebi is in the comfortable position where ETH, the Swiss National Science Foundation and private foundations fund his research generously.

Not least it needs other research groups in the surrounding environment. According to Aebi, “These interactions, which extend beyond departmental and university boundaries, are the decisive advantage of the location.” That’s why he has become an advocate of ”Life Science Zurich”, an activity supported jointly by ETH and the University whose intention is to promote and utilise interactions and synergies in this field of teaching and research.

Extending teaching to social competencies

Aebi thinks the main potential for improvements lies in the teaching. He includes support for doctoral students and post-docs in this. However, the professor is concerned not just to help young talent researchers to swot up on more specialist knowledge. He also wants to communicate “soft skills” such as teamworking ability or how cultural diversity can be used as a stimulating environment. Aebi is certain that “Many of the staff really appreciate the international environment as one of the high points in their daily work.”