  We present a formalism to describe proton emission from odd-odd nuclei based
on a scattering like approach. Special emphasis is given to the case of
transitions between states with different deformations. As an example we
estimate the proton half-life of the odd-odd nucleus $^{58}$Cu. Our
calculations show that the change of deformation in the decay process has a
significant influence on the half-life. In addition, the angular momentum
coupling of proton and neutron orbitals can result in an important
$K$-hindrance of the decay. To fully account for the observed half-life in
$^{58}$Cu, one has to consider a shape mixing in the final state.
