The magnetic and electronic investigations of PuCo1 xTxGa5 compounds, with x 1/4 0:1 and 0.2 for T 1/4 Fe and x 1/4 0:1 for Ni, are carried out by magnetization and specific heat measurements. Whereas comparison of the results obtained on the CeCo1xRhxIn5 and PuCo1xRhxGa5 series revealed strong correlation between the superconducting temperature transition and the unit cell ratio c/a in this structure, it is shown that in the cases of Fe and Ni, Tc is suppressed faster than when replacing Co by Rh. This observation reveals the crucial role in bonding and hybridization of the 5f electrons with the neighboring elements. ; JRC.E.6-Actinides research