Processive enzymes kept on a leash: How cellulase activity in multienzyme complexes directs nanoscale deconstruction of cellulose

Krisztina Zajki-Zechmeister, Gaurav Singh Kaira, Manuel Eibinger, Klara Seelich, Bernd Nidetzky*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Biological deconstruction of polymer materials gains efficiency from the spatiotemporally coordinated action of enzymes with synergetic function in polymer chain depolymerization. To perpetuate enzyme synergy on a solid substrate undergoing deconstruction, the overall attack must alternate between focusing the individual enzymes locally and dissipating them again to other surface sites. Natural cellulases working as multienzyme complexes assembled on a scaffold protein (the cellulosome) maximize the effect of local concentration yet restrain the dispersion of individual enzymes. Here, with evidence from real-time atomic force microscopy to track nanoscale deconstruction of single cellulose fibers, we show that the cellulosome forces the fiber degradation into the transversal direction, to produce smaller fragments from multiple local attacks (“cuts”). Noncomplexed enzymes, as in fungal cellulases or obtained by dissociating the cellulosome, release the confining force so that fiber degradation proceeds laterally, observed as directed ablation of surface fibrils and leading to whole fiber “thinning”. Processive cellulases that are enabled to freely disperse evoke the lateral degradation and determine its efficiency. Our results suggest that among natural cellulases, the dispersed enzymes are more generally and globally effective in depolymerization, while the cellulosome represents a specialized, fiber-fragmenting machinery.

Original languageEnglish
Pages (from-to)13530-13542
Number of pages13
JournalACS Catalysis
Issue number21
Publication statusPublished - 5 Nov 2021


  • Cellulose
  • Complexed and noncomplexed cellulases
  • Enzyme assembly
  • Enzyme synergy
  • Polymer deconstruction
  • Processive depolymerization

ASJC Scopus subject areas

  • Catalysis
  • General Chemistry


Dive into the research topics of 'Processive enzymes kept on a leash: How cellulase activity in multienzyme complexes directs nanoscale deconstruction of cellulose'. Together they form a unique fingerprint.

Cite this