A researcher at the ULg’s Centre for Protein Engineering has discovered the structure of a protein of bacterial origin which is a member of the expansins family, well known in the world of plants. The research, which has been published in the PNAS journal, also shows that this protein plays a determining role in the ability of the bacteria Bacillus subtilis to colonise plants through their roots. This could be an extra lead in the research for natural methods in the fight against infectious diseases in agriculture.

The ULg’s Centre for Protein Engineering (CIP) today employs around seventy people. All its researchers study, amongst other subjects, the proteins that bacteria produce to form an external cell wall which is sufficiently solid to serve it as an exoskeleton and to resist external attacks. Certain antibiotics such as penicillin prevent the synthesis of a specific compound in this cell wall, leading the bacteria to quite literally explode. The bacteria nonetheless deploy different resistance mechanisms against these antibiotics, including the production of proteins which break down the latter before they can act. Understanding how bacteria build their cell walls is a fundamental issue in research terms, but also in clinical research. The resistance of bacteria to antibiotics, which are translated by nosocomial infections in particular, has become a matter of medical urgency (see also the article Antibiotics against Bacteria).

An important stage in this work on bacterial proteins is crystallography. This consists in determining the three dimensional structure of chains of amino acids folded in on themselves and which constitute genuine engines allowing cells to function. At the CIP, this is Frédéric Kerff’s speciality. This young FNRS researcher spends numerous hours each week in a small room which holds thousands of test tubes, each one containing a particular protein in solution. With all due respect, there is something off the Smurf’s Gargamel in Frédéric Kerff. This is neither malicious nor ridiculous, but simply underlines his attitude when in front of the test tubes: a pinch of this, a dash of that, a drop of this… Frédéric Kerff works neither with toad’s spit nor snake poison, but with ‘precipitating agents.’