  We suggest a new mechanism for the energy loss of fast heavy quarks in
quark-gluon plasma. This mechanism is based on pion production caused by the
anomalous chromomagnetic quark-gluon-pion interaction induced by strong
topological fluctuations of the gluon fields represented by instantons. We
found that this mechanism gives a considerable contribution to the collisional
energy loss of a heavy quark in quark-gluon plasma, which shows a nontrivial
role of nonperturbative phenomena in strongly interacting quark-gluon plasma.
