Structural and functional analysis of the truncated Fibrobacter succinogenes 1,3-1,4-β-D-glucanase mutant Y42L and inhibitor complex

Autor: Wen-Chin Chang, 張文進
Rok vydání: 2012
Druh dokumentu: 學位論文 ; thesis
Popis: 100
Fibrobacter succinogenes 1,3-1,4-β-D-glucanase (Fsβ-glucanase, E.C.3.2.1.73) specifically hydrolyze the β-1,4 bonds when β-1,3 linkages are located prior to the β-1,4 bonds in β-D-glucan or lichenan. The final hydrolyzed products are tri- and penta- saccharides. Three calcium ions and two tris molecules are found in the truncated Fsβ-glucanase mutant Y42L structure. The first calcium ion is located at the same position as that of wild type. The second Ca2+ ion was found near the residues Phe152 and Glu154 on the protein’s surface, and the third one near the active site residue Asp202. Moreover, a tris molecule interacts with the catalytic residues Glu56 and Glu60 at subunit -1 of substrate. Based on the kinetic data, it is shown that the third Ca2+ ion and tris molecule are non-competitive and competitive inhibitors for the enzyme, respectively.
Databáze: Networked Digital Library of Theses & Dissertations