ñ-Mannosidase (, ñ-<small>D</small>-mannosidase, p-nitrophenyl-ñ-mannosidase, ñ-<small>D</small>-mannopyranosidase, 1,2-ñ-mannosidase, 1,2-ñ-<small>D</small>-mannosidase, exo-ñ-mannosidase) is an enzyme involved in the cleavage of the ñ form of mannose. Its systematic name is ñ-<small>D</small>-mannoside mannohydrolase.
Humans express the following three ñ-mannosidase isoenzymes:
It can be utilized in experiments that determine the effects of the presence or absence of mannose on specific molecules, such as recombinant proteins that are used in vaccine development.
A deficiency can lead to ñ-mannosidosis.