An enzyme capable of hydrolyzing (i.e., breaking) interior bonds in the oligosaccharide molecular branches of a glycoprotein molecule. That is, the enzyme is capable of cutting a sugar-to-sugar bond anywhere within the sugar polymer molecule (depending, of course, on the specificity of the enzyme). This is in contrast to an exoglycosidase, which must cut away at the polymer from the outside, that is, from the free end, one unit (or section as the case may be) at a time.
An enzyme that hydrolyzes (cuts) only a terminal (i.e., end) bond in the oligosaccharide (molecular) branch(es) of a glycoprotein.