Engineering of a chitin deacetylase to generate tailor-made chitosan polymers

Martin Bonin, Antonia L. Irion, Anika Jürß, Sergi Pascual, Stefan Cord-Landwehr, Antoni Planas, Bruno M. Moerschbacher

Producció científica: Article en revista indexadaArticleAvaluat per experts

Resum

AU Chitin: Pleaseconfirmthatallheadinglevelsarerepresentedcorrectly deacetylases (CDAs) emerge as a valuable tool to produce : chitosans with a nonrandom distribution of N-acetylglucosamine (GlcNAc) and glucosamine (GlcN) units. We hypothesized before that CDAs tend to bind certain sequences within the substrate matching their subsite preferences for either GlcNAc or GlcN units. Thus, they deacetylate or Nacetylate their substrates at nonrandom positions. To understand the molecular basis of these preferences, we analyzed the binding site of a CDA from Pestalotiopsis sp. (PesCDA) using a detailed activity screening of a site-saturation mutagenesis library. In addition, molecular dynamics simulations were conducted to get an in-depth view of crucial interactions along the binding site. Besides elucidating the function of several amino acids, we were able to show that only 3 residues are responsible for the highly specific binding of PesCDA to oligomeric substrates. The preference to bind a GlcNAc unit at subsite −2 and −1 can mainly be attributed to N75 and H199, respectively. Whereas an exchange of N75 at subsite −2 eliminates enzyme activity, H199 can be substituted with tyrosine to increase the GlcN acceptance at subsite −1. This change in substrate preference not only increases enzyme activity on certain substrates and changes composition of oligomeric products but also significantly changes the pattern of acetylation (PA) when N-acetylating polyglucosamine. Consequently, we could clearly show how subsite preferences influence the PA of chitosans produced with CDAs.

Idioma originalAnglès
Número d’article3002459
RevistaPLoS Biology
Volum22
Número1
DOIs
Estat de la publicacióPublicada - de gen. 2024

Fingerprint

Navegar pels temes de recerca de 'Engineering of a chitin deacetylase to generate tailor-made chitosan polymers'. Junts formen un fingerprint únic.

Com citar-ho