Visualization of cellobiohydrolase I from trichoderma reesei moving on crystalline cellulose using high-speed atomic force microscopy

Cellulases hydrolyze β-1,4-glucosidic linkages of insoluble cellulose at the solid/liquid interface, generating soluble cellooligosaccharides. We describe here our method for real-time observation of the behavior of cellulase molecules on the substrate, using high-speed atomic force microscopy (HS-AFM). When glycoside hydrolase family 7 cellobiohydrolase from Trichoderma reesei (TrCel7A) was incubated with crystalline cellulose, many enzyme molecules were observed to move unidirectionally on the surface of the substrate by HS-AFM. The velocity of the moving molecules of TrCel7A on cellulose I crystals was estimated by means of image analysis.