  The space-like elastic form factor of heavy-light pseudoscalar mesons is
investigated within a light-front constituent quark model in order to evaluate
the Isgur-Wise form factor. The relativistic composition of the constituent
quark spins is properly taken into account using the Melosh rotations, and
various heavy-meson wave function are considered, including the eigenfunctions
of an effective light-front mass operator reproducing meson mass spectra. It is
shown that in a wide range of values of the recoil the Isgur-Wise form factor
exhibits a moderate dependence upon the choice of the heavy-meson wave function
and is mainly governed by the effects of the confinement scale.
