PhD ceremony: Mr. L.W. Schwab, 13.15 uur, Academiegebouw, Broerstraat 5, Groningen
Thesis: Polyamide synthesis by hydrolases
Promotor(s): prof. K. Loos
Faculty: Mathematics and Natural Sciences
In the past decades enzymes have become part of the chemists’ toolbox and they have proven to be effective in different organic reactions. Polymers produced by enzymes include polysaccharides, polyesters and even vinyl polymers. The synthesis of polyamides by enzymatic pathways is however not extensively studied. This project was started to synthesize polyamides by enzyme catalysis.
The enzymatic (Candida antarctica lipase B) ring-opening polymerization of b-propiolactam a 4-membered lactam ring in toluene is introduced. Optimally, the enzyme is dried for 24 hours over P2O5. A reaction at 55 °C yields enzyme with the highest DP.
Enzymatic catalysis can also be applied to the polycondensation of diesters and diamines. The polycondensation diesters and diamines is followed with ATR-FTIR spectroscopy over time. A comparison is made between the rate of amide formation by the uncatalyzed reaction and by the enzymatic reaction. At 60 °C the enzymatic reaction is slower than the non-catalyzed reaction.
Papain, a protease, catalyzes the homopolymerization and copolymerization of amino acid esters. Four hydrophobic amino acids were used, tyrosine, leucine, phenylalanine and tryptophan. A detailed analysis of the composition is done by MALDI-ToF mass spectrometry. When the chains grow longer in general more leucine is present and less tryptophan is incorporated in the chains. Tyrosine is slightly more reactive than phenylalanine. Phenylalanine produces short chains with apparently a low solubility.
Papain is able to synthesize amide bonds between amino acids and diamines. A series of monoamides based on protected glycine, phenylalanine and leucine and aromatic diamines can be synthesized catalyzed by papain.
The timing, route, and destination for godwit migration is learned rather than innate. Researchers at the University of Groningen discovered this in a daring experiment, which has been published in the latest issue of the journal Current Biology.
The grant is worth EUR 500,000, of which Avraamidou and Sburlea receive around EUR 100,000.
George Azzopardi and Guru Swaroop Bennabhaktula from the Faculty of Science and Engineering have won the Ben Feringa Impact Award 2023 for their project ‘4NSEEK; Forensic Against Sexual Exploitation of Children’. In the ‘students’ category, Nine van...
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