INTERACTION OF CELLODEXTRINS WITH LYSOZYME - NECESSITY OF 2-ACETAMIDO GROUP FOR BINDING AND HYDROLYSIS

The cellodextrins (Gl2, Gl3, Gl4, Gl5, and Gl6)4 4 Abbreviations employed are: Gl, glucose; Gl2, cellobiose; Gl3, cellotriose; Gl4, cellotetraose; Gl5, cellopentaose; Gl6, cellohexaose; NAG, N-acetylglucosamine; NAG2, di-N-acetylchitobiose; NAG3, tri-N-acetylchitotriose. have been reacted with lysozyme, and have been shown to result in no hydrolyses of glycosidie linkages. The over-all reaction and initial lag period in the hydrolysis of a known lysozyme substrate, tri-N-acetylchitotriose (NAG3) are not affected by the addition of Gl6. In addition, equilibrium dialysis studies establish an upper limit for the binding constants of all five cellodextrins of Ka ≤ 200 m-1. The results of this study indicate that the β-(1-4)-linked glucopyranoside oligomer structure is not sufficient to yield productive binding of substrate to lysozyme, and indicate the necessity of the N-acetyl group for substrate binding. © 1969.