Structural and Electronic Modulations of Lytic Polysaccharide Monooxygenase (LPMO) upon Chitin Binding: Insights from X-ray Spectroscopy

This report investigates the structural and electronic changes at the copper (Cu) site of the SmAA10A LPMO upon binding with chitin, utilizing a suite of spectroscopic and computational methods. Herein, we present the first reported X-ray Absorption (XAS) and Emission (XES) spectroscopic data on substrate-bound LPMO.

By comparing the Cu(II) and Cu(I) states of SmAA10A in both the chitin-bound and unbound states, we provide insights into the structural adjustments facilitating substrate specificity and the productive catalytic turnover of the enzyme. Our results indicate a binding-induced conformational change in Cu(I) site geometry and concurrent modulations to the electronic structure, which prime the enzyme for targeted C–H activation.