Inhibition and detection of 15-lipoxygenase-1
|PhD ceremony:||Mr N. (Nick) Eleftheriadis|
|When:||January 13, 2017|
|Supervisors:||prof. dr. H.J. (Hidde) Haisma, prof. dr. F.J. (Frank) Dekker|
|Where:||Academy building RUG|
In his thesis Nick Eleftheriadis has described the design of new inhibitors of human 15-lipoxygenase-1 (15-LOX-1) using a novel approach for fragment–based screening. 15-LOX-1 is an important mammalian lipoxygenase and plays a crucial role in the biosynthesis of inflammatory signaling molecules, having a regulatory role in several inflammatory lung diseases such as asthma, chronic obstructive pulmonary disease (COPD) and chronic bronchitis. Recently also roles in various diseases of the central nervous system like Alzheimer’s and Parkinson’s as well as stroke have been described. Novel potent inhibitors and activity-based probes of 15-LOX-1 are urgently required to explore the role of this enzyme further and enable drug discovery efforts. This thesis consists of part A and part B with related but distinct topics.
In Part A the design of new inhibitors of 15-LOX-1 using a novel approach for fragment–based screening has been described. This method employs diversely substituted scaffolds for substitution oriented screening (SOS) in order to find lead compounds for 15-LOX-1 inhibition. The initial hit structures have been optimized using structure-based design and molecular modeling studies resulting in various potent inhibitors. The best inhibitors were evaluated in cell-based studies and ex vivo studies in mouse precision-cut lung slices, where they showed anti-inflammatory and neuroprotective effects.
In Part B the development of a novel probe for activity-based labeling of 15-LOX-1 has been described. We have created for the first time an activity-based probe as an efficient chemical tool for activity-based labeling of recombinant 15-LOX-1 that also provides 15-LOX-1 activity dependent labeling in cell lysates and tissue. By mimicking the natural substrate of the enzyme, activity-based probes have been designed that covalently bind to the active enzyme. The probes are tagged with a terminal alkene as chemical reporter that has been employed for bioorthogonal linkage of a detectable biotin functionality via the oxidative Heck reaction.