  In the present work we consider the influence on the heavy quark correlators
due to the instanton background in the framework of instanton liquid model
(ILM) of QCD vacuum by taking into account also the perturbative gluon effects.
For a single heavy quark this leads to the mass shift due to the
direct-instanton nonperturbative and ILM modified perturbative contributions,
respectively. In the heavy quark-antiquark ($Q\bar{Q}$) sector we obtain the
potential consisting the direct instanton induced part and the one-gluon
exchange (OGE) perturbative part which is screened at large distances due to
the nonperturbative dynamics. At the region of interest corresponding to the
heavy quark physics the screening effect in OGE can be well approximated by a
Yukawa-type potential in terms of the dynamically generated gluon mass.
  A possible implication of the present studies to the phenomenology of heavy
quarkonium is also discussed.
