  The interplay of phase separation and dynamical arrest can lead to the
formation of gels and glasses, which is relevant for such diverse fields as
hard and soft condensed matter physics, materials science, food engineering and
pharmaceutical industry. Here, the non-equilibrium states as well as the
interactions of globular proteins are analyzed. Lysozyme in brine is chosen as
a model system with short-range attractions. The metastable gas-liquid binodal
and the dynamical arrest line as well as the second virial coefficient $B_2$
have been determined for various solution conditions by cloud-point
measurements, optical microscopy, centrifugation experiments and light
scattering. If temperature is expressed in terms of $B_2$, the binodals
obtained under various conditions fall onto a master curve, as suggested by the
extended law of corresponding states. Arrest lines for different salt
concentrations overlap within experimental errors, whereas they do not overlap
if the temperature axis is replaced by $B_2$. This indicates that the binodals
are not sensitive to the details of the potential, but can be described by one
integral parameter, i.e. $B_2$, whereas the arrest line appears governed by its
attractive part. The experimental findings are supported by numerical results
of the non-equilibrium self-consistent generalized Langevin equation theory.
