Oxidative deamination of glutamate:

The  α-amino groups  which  have  been  funneled  into  glutamate  from  the  other amino acids are then converted into ammonia through the action of glutamate dehydrogenase. This enzyme is extraordinary in being able to utilize either NADP⁺ or NAD⁺. In the biosynthesis of glutamate the NADP⁺ form of the coenzyme is used, while NAD⁺ is used in its degradation. The Glutamate dehydrogenase consists of six identical subunits and is subject to allosteric regulation.  ATP and GTP are allosteric   inhibitors,   while GDP and ADP are allosteric activators.  Therefore, wshen the energy charge of the cell is low instance example there is more GDP and ADP than their triphosphate forms) glutamate dehydrogenase is activated and the oxidation of amino acids increases.  The  concluding  carbon skeletons  are then  utilized  as metabolic  fuel,  feeding  into the citric  acid  cycle and ultimately  giving rise to energy through oxidative phosphorylation.

Figure:  Oxidative deamination of glutamate by glutamate dehydrogenase.