Bustin Katelyn A, Abbas Arwa, Wang Xie, Abt Michael C, Zackular Joseph P, Matthews Megan L
Department of Chemistry, University of Pennsylvania, Philadelphia, PA, United States.
Division of Protective Immunity, Children's Hospital of Pennsylvania, Philadelphia, PA, United States.
Front Pharmacol. 2023 Jan 26;14:1074619. doi: 10.3389/fphar.2023.1074619. eCollection 2023.
Many enzymes require post-translational modifications or cofactor machinery for primary function. As these catalytically essential moieties are highly regulated, they act as dual sensors and chemical handles for context-dependent metabolic activity. is a major nosocomial pathogen that infects the colon. Energy generating metabolism, particularly through amino acid Stickland fermentation, is central to colonization and persistence of this pathogen during infection. Here using activity-based protein profiling (ABPP), we revealed Stickland enzyme activity is a biomarker for infection (CDI) and annotated two such cofactor-dependent Stickland reductases. We structurally characterized the cysteine-derived pyruvoyl cofactors of D-proline and glycine reductase in cultures and showed through cofactor monitoring that their activity is regulated by their respective amino acid substrates. Proline reductase was consistently active in toxigenic , confirming the enzyme to be a major metabolic driver of CDI. Further, activity-based hydrazine probes were shown to be active site-directed inhibitors of proline reductase. As such, this enzyme activity, its druggable cofactor modality, is a promising therapeutic target that could allow for the repopulation of bacteria that compete with for proline and therefore restore colonization resistance against in the gut.
许多酶需要翻译后修饰或辅因子机制来发挥主要功能。由于这些催化必需的部分受到高度调控，它们充当了上下文依赖性代谢活动的双重传感器和化学手柄。[某种细菌名称]是一种主要的医院病原体，可感染结肠。能量产生代谢，特别是通过氨基酸斯特克兰德发酵，对于该病原体在感染期间的定殖和持续存在至关重要。在这里，我们使用基于活性的蛋白质谱分析（ABPP），揭示了斯特克兰德酶活性是[某种细菌名称]感染（CDI）的生物标志物，并注释了两种此类依赖辅因子的斯特克兰德还原酶。我们在[某种细菌名称]培养物中对D - 脯氨酸和甘氨酸还原酶的半胱氨酸衍生的丙酮酸辅因子进行了结构表征，并通过辅因子监测表明它们的活性受各自氨基酸底物的调节。脯氨酸还原酶在产毒的[某种细菌名称]中始终具有活性，证实该酶是CDI的主要代谢驱动因素。此外，基于活性的肼探针被证明是脯氨酸还原酶的活性位点定向抑制剂因此，这种酶活性及其可成药的辅因子模式是一个有前景的治疗靶点，它可以使与[某种细菌名称]竞争脯氨酸的细菌重新定殖，从而恢复肠道对[某种细菌名称]的定植抗性。
