  We examine the conventional picture that gluons carry about half of the
nucleon momentum in the asymptotic limit. We reveal that this large fraction is
due to an unsuitable definition of the gluon momentum in an interacting theory.
If defined in a gauge-invariant and consistent way, the asymptotic gluon
momentum fraction is computed to be only about one fifth. This result suggests
that the asymptotic limit of the nucleon spin structure should also be
reexamined. Possible experimental test of our finding is discussed in terms of
novel parton distribution functions.
