Enzymatic Destruction of Cellulose: Characteristics of the Kinetic Interaction of Lytic Polysaccharide Monooxygenases and Individual Cellulases

This paper studies the characteristics of the kinetic interaction of lytic polysaccharide monooxygenases (LPMOs) from Thielavia terrestris (TtLPMO), Penicillium verruculosum (PvLPMO), and Trichoderma reesei (TrLPMO) with purified cellobiohydrolases (CBH I and CBH II) and endoglucanase II (EG II) of P. verruculosum during the enzymatic destruction of microcrystalline (Avicel) and amorphous cellulose. TtLPMO belongs to the C1-type of LPMOs, while PvLPMO and TrLPMO are of the mixed C1/C4-type, according to the generally accepted classification of this class of oxidases. Under the action of any of the three LPMO together with CBH II or EG II on Avicel or amorphous cellulose, respectively, the enzymes displayed synergism, which was manifested in an increase in the yield of reducing sugars (RS). The synergism was expressed to the greatest extent in the initial reaction period. The mixtures of PvLPMO and TrLPMO with CBH I also demonstrated synergism on Avicel as a substrate, while TtLPMO, on the contrary, had an inhibitory effect on RS formation from cellulose with CBH I. The observed synergism and antagonism between LPMOs and CBH II/CBH I can be explained in terms of a simple kinetic scheme, in which the first enzyme forms additional ends of polysaccharide molecules that serve as a substrate or inhibitor for the second enzyme.

Automated summary

This study investigated the interaction characteristics between different types of LPMOs and cellulase during the enzymatic hydrolysis of cellulose, finding synergism in the initial reaction period but also some antagonism.