Fluorogenic structure activity library pinpoints molecular variations in substrate specificity of structurally homologous esterases
作者:Alex White、Andrew Koelper、Arielle Russell、Erik M. Larsen、Charles Kim、Luke D. Lavis、Geoffrey C. Hoops、R. Jeremy Johnson
DOI:10.1074/jbc.ra118.003972
日期:2018.9
and used this library to systematically interrogate esterase preference for chain length, branching patterns, and polarity to differentiate common classes of esterase substrates. Two structurally homologous bacterial esterases were screened against this library, refining their previously broad overlapping substrate specificity. Vibrio cholerae esterase ybfF displayed a preference for γ-position thioethers
细胞酯酶通过在各种底物上进行水解反应来催化许多重要的生物学功能。酯酶的滥交使底物偏好和生物学功能的分配变得复杂。为了识别控制酯酶底物识别的通用因素,我们设计了一个32位成员的荧光酯底物的结构-活性关系(SAR)库,并使用该库系统地查询酯酶对链长,分支模式和极性的偏好,以区分常见的酯酶底物。针对该文库筛选了两种结构同源的细菌酯酶,完善了它们先前广泛的重叠底物特异性。霍乱弧菌酯酶ybfF显示出对γ-位硫醚和醚的偏爱,而来自结核分枝杆菌的Rv0045c则偏爱带有或不带有硫醚的支链底物。我们确定这种底物分化部分受ybfF中单个底物选择性残基Tyr-119和Rv0045c中His-187的控制。这些残基的相互取代改变了每种酯酶的底物偏好。这项工作表明酯酶的选择性可基于过渡态稳定度进行调整,将硫醚确定为酯酶底物的未充分利用的官能团,并提供了区分结构同工酶的快速方法。该SAR库可能具有多方面的未来应用,