Premium
Preliminary results of neutron and X‐ray diffraction data collection on a lytic polysaccharide monooxygenase under reduced and acidic conditions
Author(s) -
Schröder Gabriela C.,
O'Dell William B.,
Swartz Paul D.,
Meilleur Flora
Publication year - 2021
Publication title -
acta crystallographica section f
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.572
H-Index - 37
ISSN - 2053-230X
DOI - 10.1107/s2053230x21002399
Subject(s) - protonation , chemistry , glycosidic bond , crystallography , neutron diffraction , monooxygenase , neurospora crassa , cellulose , crystal structure , photochemistry , organic chemistry , enzyme , biochemistry , ion , cytochrome p450 , mutant , gene
Lytic polysaccharide monooxygenases (LPMOs) are copper‐center enzymes that are involved in the oxidative cleavage of the glycosidic bond in crystalline cellulose and other polysaccharides. The LPMO reaction is initiated by the addition of a reductant and oxygen to ultimately form an unknown activated copper–oxygen species that is responsible for polysaccharide‐substrate H‐atom abstraction. Given the sensitivity of metalloproteins to radiation damage, neutron protein crystallography provides a nondestructive technique for structural characterization while also informing on the positions of H atoms. Neutron cryo‐crystallography permits the trapping of catalytic intermediates, thereby providing insight into the protonation states and chemical nature of otherwise short‐lived species in the reaction mechanism. To characterize the reaction‐mechanism intermediates of LPMO9D from Neurospora crassa , a cryo‐neutron diffraction data set was collected from an ascorbate‐reduced crystal. A second neutron diffraction data set was collected at room temperature from an LPMO9D crystal exposed to low‐pH conditions to probe the protonation states of ionizable groups involved in catalysis under acidic conditions.