Human African trypanosomiasis caused by the infection of Trypanosoma brucei (T. brucei) is a fatal disease if untreated. Today treatments are either very toxic, very complicated to administer or limited to the first phase of the infection, thus new potent and safe drugs are needed. The aim of the thesis was to investigate the AMP-activated protein kinase (AMPK) in T. brucei. AMPK is a heterotrimeric complex known for its role in maintaining energy homeostasis in the cell by detecting the ratio AMP:ATP. To this end the corresponding subunits were identified by sequence alignment and confirmed by a modified bacterial adenylate two-hybrid system : catalytic subunits α (TbAMPKα1: Tb927.3.4560, TbAMPKα2: Tb927.10.5310) and regulatory subunits β (Tb927.8.2450) and γ (Tb927.10.3700). The complex was expressed using a polycistronic expression system and the purified complex was biochemically characterized. Finally, the importance of the catalytic subunits were confirmed in vivo on designed knock-out and knock-down strains.