Cell-wall degrading enzyme variants
    7.
    发明申请
    Cell-wall degrading enzyme variants 审中-公开
    细胞壁降解酶变体

    公开(公告)号:US20050250181A1

    公开(公告)日:2005-11-10

    申请号:US10926709

    申请日:2004-08-26

    CPC分类号: C11D3/38636 C12N9/88

    摘要: The present invention relates to variants of a cell-wall degrading enzyme having a beta-helix structure, which variant has at least one substituent in a position determined by identifying all residues potentially belonging to a stack; characterizing the stack as interior or exterior; characterizing the stack as polar, hydrophobic or aromatic/heteroaromatic based on the dominating characteristics of the parent or wild-type enzyme stack residues and/or its orientation relative to the beta-helix (interior or exterior); optimizing all stack positions of a stack either to hydrophobic aliphatic amino acids, hydrophobic aromatic or polar amino acids by allowing mutations within one or all positions to amino acids belonging to one of these groups; measuring thermostability of the variants by DSC or an application-related assay such as a Pad-Steam application test; and selecting the stabilized variants. Variants of a wild-type parent pectate lyase (EC 4.2.2.2) having the conserved amino acid residues D111, D141 or E141, D145, K165, R194 and R199 when aligned with the pectate lyase comprising the amino acid sequence of SEQ ID NO: 2 are preferred.

    摘要翻译: 本发明涉及具有β-螺旋结构的细胞壁降解酶的变体,该变体具有至少一个取代基,其位置通过鉴定潜在属于堆叠的所有残基而确定; 将堆栈表征为内部或外部; 基于母体或野生型酶堆残基的主导特征和/或其相对于β-螺旋(内部或外部)的取向,将所述叠层表征为极性,疏水性或芳族/杂芳族化合物; 通过在属于这些基团之一的氨基酸的一个或所有位置内允许突变将堆叠的所有堆叠位置优化为疏水性脂族氨基酸,疏水性芳族或极性氨基酸; 通过DSC测量变体的热稳定性或应用相关测定,例如Pad-Steam应用测试; 并选择稳定的变体。 当与包含SEQ ID NO:1的氨基酸序列的果胶酸裂合酶比对时,具有保守氨基酸残基D111,D141或E141,D145,K165,R194和R199的野生型亲本果胶酸裂解酶(EC 4.2.2.2) 2是优选的。