Exo-arabinanase of Penicillium chrysogenum able to release arabinobiose from α-1,5-L-arabinan

An exo-arabinanase, designated Abnx, was purified from a culture filtrate of Penicillium chrysogenum 31B by ammonium sulfate precipitation, anion-exchange chromatography, and hydrophobic chromatography. Abnx had an apparent molecular mass of 47 kDa. The enzyme released only arabinobiose from the nonreducing terminus of alpha -1,5-L-arabinan and shelved no activity towards p-nitrophenyl-alpha -L-arabinofuranoside and alpha -1,5-L-arabinofuranobiose. Abnx is the first enzyme with this mode of action.