MyJournals Home  

RSS FeedsEngineering chitinolytic activity into a cellulose-active lytic polysaccharide monooxygenase provides insights into substrate specificity [Enzymology] (Journal of Biological Chemistry)

 
 

13 december 2019 11:02:47

 
Engineering chitinolytic activity into a cellulose-active lytic polysaccharide monooxygenase provides insights into substrate specificity [Enzymology] (Journal of Biological Chemistry)
 


Lytic polysaccharide monooxygenases (LPMOs) catalyze oxidative cleavage of recalcitrant polysaccharides such as cellulose and chitin and play an important role in the enzymatic degradation of biomass. Although it is clear that these monocopper enzymes have extended substrate-binding surfaces for interacting with their fibrous substrates, the structural determinants of LPMO substrate specificity remain largely unknown. To gain additional insight into substrate specificity in LPMOs, here we generated a mutant library of a cellulose-active family AA10 LPMO from Streptomyces coelicolor A3(2) (ScLPMO10C, also known as CelS2) having multiple substitutions at five positions on the substrate-binding surface that we identified by sequence comparisons. Screening of this library using a newly-developed MS-based high-throughput assay helped identify multiple enzyme variants that contained four substitutions and exhibited significant chitinolytic activity and a concomitant decrease in cellulolytic activity. The chitin-active variants became more rapidly inactivated during catalysis than a natural chitin-active AA10 LPMO, an observation likely indicative of suboptimal substrate binding leading to autocatalytic oxidative damage of these variants. These results reveal several structural determinants of LPMO substrate specificity and underpin the notion that productive substrate binding by these enzymes is complex, depending on a multitude of amino acids located on the substrate-binding surface.


 
246 viewsCategory: Biochemistry
 
SDF2-like protein 1 (SDF2L1) regulates the endoplasmic reticulum localization and chaperone activity of ERdj3 protein [Cell Biology] (Journal of Biological Chemistry)
The ribosome assembly factor Nop53 controls association of the RNA exosome with pre-60S particles in yeast [RNA] (Journal of Biological Chemistry)
 
 
blog comments powered by Disqus


MyJournals.org
The latest issues of all your favorite science journals on one page

Username:
Password:

Register | Retrieve

Search:

Biochemistry


Copyright © 2008 - 2024 Indigonet Services B.V.. Contact: Tim Hulsen. Read here our privacy notice.
Other websites of Indigonet Services B.V.: Nieuws Vacatures News Tweets Nachrichten