The aroma of TEMED as an activation and stabilizing signal for the antibacterial enzyme HEWL

PLoS One. 2020 May 19;15(5):e0232953. doi: 10.1371/journal.pone.0232953. eCollection 2020.

Abstract

The unpleasant smell released from dead bodies, may serve as an alarm for avoiding certain behaviour or as feeding or oviposition attractants for animals. However, little is known about their effect on the structure and function of proteins. Previously, we reported that using the aroma form of TEMED (a diamine), representative of the "smell of death", could completely inhibit the fibril formation of HEWL, as an antibacterial enzyme, and a model protein for fibrillation studies. To take this further, in this study we investigated the kinetics of TEMED using a number of techniques and in particular X-ray crystallography to identify the binding site(s) of TEMED and search for hotspot(s) necessary to inhibit fibril formation of HEWL. Structural data, coupled with other experimental data reported in this study, revealed that TEMED completely inhibited fibril formation and stabilized the structure of HEWL through enhancement of the CH-Π interaction and binding to an inhibitor hotspot comprised of residues Lys33, Phe34, Glu35 and Asn37 of HEWL. Additionally, results from this study showed that the binding of TEMED increased the activity and thermal stability of HEWL, helping to improve the function of this antibacterial enzyme. In conclusion, the role of the "smell of death", as an important signal molecule affecting the activity and stability of HEWL was greatly highlighted, suggesting that aroma producing small molecules can be signals for structural and functional changes in proteins.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amyloid / metabolism
  • Animals
  • Anti-Bacterial Agents
  • Binding Sites
  • Chickens / metabolism
  • Crystallography, X-Ray
  • Ethylenediamines / chemistry*
  • Female
  • Hydrogen-Ion Concentration
  • Kinetics
  • Models, Molecular
  • Muramidase / metabolism*
  • Odorants / analysis*

Substances

  • Amyloid
  • Anti-Bacterial Agents
  • Ethylenediamines
  • N,N,N',N'-tetramethylethylenediamine
  • hen egg lysozyme
  • Muramidase

Grants and funding

We acknowledge financial support of the Presidential Deputy for Science and Technology, the Institute for Research in Fundamental Sciences and the Iranian Light Source Facility for the opportunity to be users at the ALBA synchrotron program 2017 (proposal number ID2017062245). We acknowledge financial support of the OPEN SESAME for the two months student training fellowship for Miss Zahra Seraj (2018) and the Ministry of Science and Technology of Iran for six months research placement of Miss Zahra Seraj at University of Groningen, Netherlands.