The trehalose biosynthesis pathway has recently received attention for therapeutic intervention combating infectious diseases caused by bacteria, helminths or fungi. Trehalose-6-phosphate phosphatase (TPP) is a key enzyme of the most common trehalose biosynthesis pathway and a particularly attractive target owing to the toxicity of accumulated trehalose-6-phosphate in pathogens.

Here, we characterised TPP-like proteins from bacterial pathogens implicated in nosocomial infections in terms of their steady-state kinetics as well as pH- and metal-dependency of their enzymatic activity. Analysis of the steady-state kinetics of recombinantly expressed enzymes from Acinetobacter baumannii, Corynebacterium diphtheriae and Pseudomonas stutzeri yielded similar kinetic parameters as those of other reported bacterial TPPs. In contrast to nematode TPPs, the divalent metal ion appears to be bound only weakly in the active site of bacterial TPPs, allowing the exchange of the resident magnesium ion with other metal ions. Enzymatic activity comparable to the wild-type enzyme was observed for the TPP from P. stutzeri with manganese, cobalt and nickel. Analysis of the enzymatic activity of S. maltophilia TPP active site mutants provides evidence for the involvement of four canonical aspartate residues as well as a strictly conserved histidine residue of TPP-like proteins from bacteria in the enzyme mechanism. That histidine residue is a member of an interconnected network of five conserved residues in the active site of bacterial TPPs which likely constitute one or more functional units, directly or indirectly cooperating to enhance different aspects of the catalytic activity.

海藻糖的生物合成途径近来已受到关注，以对抗由细菌，蠕虫或真菌引起的传染病的治疗干预。海藻糖6-磷酸磷酸酶（TPP）是最常见的海藻糖生物合成途径的关键酶，由于在病原体中积累的海藻糖6-磷酸具有毒性，因此是一个特别有吸引力的靶标。

在这里，我们从细菌性病原体中鉴定出TPP样蛋白，这些蛋白与医院感染有关，涉及稳态动力学以及酶活性的pH和金属依赖性。鲍曼不动杆菌，白喉棒状杆菌和斯氏假单胞菌的重组表达酶的稳态动力学分析产生的动力学参数与其他报道的细菌TPP相似。与线虫TPP相比，二价金属离子似乎只在细菌TPP的活性位点弱结合，从而使残留的镁离子与其他金属离子交换。对于来自斯图氏假单胞菌的TPP，观察到与野生型酶相当的酶活性。含锰，钴和镍。嗜麦芽孢杆菌TPP活性位点突变体的酶促活性分析提供了四个典型的天冬氨酸残基以及来自细菌的TPP样蛋白的严格保守的组氨酸残基参与酶机制的证据。该组氨酸残基是细菌TPPs活性位点中五个保守残基的互连网络的成员，其可能构成一个或多个功能单元，直接或间接地协同作用以增强催化活性的不同方面。