  We define a degenerate affine version of the walled Brauer algebra, that has
the same role plaid by the degenerate affine Hecke algebra for the symmetric
group algebra. We use it to prove a higher level mixed Schur-Weyl duality for
gl_N. We consider then families of cyclotomic quotients of level two which
appear naturally in Lie theory and we prove that they inherit from there a
natural grading and a graded cellular structure.
