IDENTIFICATION OF ACTIVE-SITE RESIDUES IN ASPERGILLUS-FICUUM EXTRACELLULAR PH 2.5 OPTIMUM ACID-PHOSPHATASE

Primary structure elucidation of peptides generated by cyanogen bromide, endoproteinase Glu-C, and clostripain cleavage of an Aspergillus ficuum extracellular pH optimum 2.5 acid phosphatase identified a region which contains the active site of the enzyme. The 23-residue segment contains the fragment RHGXRXP, which is homologous to acid phosphatases from Saccharomyces spp., Aspergillus ficuum, mammals, and bacteria. Homologous or conservative substitutions are observed in the 10-amino acid fragment preceding this region. © 1993 Academic Press, Inc.