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 α-1,5-l-arabinan and showed no activity towards p-nitrophenyl-α-l-arabinofuranoside and α-1,5-l-arabinofuranobiose. Abnx is the first enzyme with this mode of action.