SAXS derived scattering curves of a concentration range of PICK1 in complex with Tat-P4-(C5)2 on absolute scale show minor concentration dependent aggregation. Pair distance distribution function (pddf) of a concentration range of PICK1 in presence of Tat-P4-(C5)2, indicating a smaller complex than for PICK1 in absence of Tat-P4-(C5)2. 