A Noncommutative M-Theory Five-brane
  We investigate, in a certain decoupling limit, the effect of having a constant C-field on the M-theory five-brane using an open membrane probe. We define an open membrane metric for the five-brane that remains non-degenerate in the limit. The canonical quantisation of the open membrane boundary leads to a noncommutative loop space which is a functional analogue of the noncommutative geometry that occurs for D-branes. 
E. Bergshoeff, D. S. Berman, J. P. van der Schaar, P. Sundell