THE COMPLETE PRIMARY STRUCTURE ELUCIDATION OF ASPERGILLUS-FICUUM (NIGER), PH-6.0, OPTIMUM ACID-PHOSPHATASE BY EDMAN DEGRADATION

The primary structure of the Aspergillus ficuum (niger) NRRL 3135 extr acellular, pH 6.0, optimum acid phosphatase (E.C.3.1.3.2) was elucidat ed by gas phase sequencing. It was deduced by sequence overlap of pept ides obtained from trypsin, chymotrypsin, clostripain, and cyanogen br omide digests of the pyridylethylated protein. The mature, active prot ein is composed of 583 amino acids, including 13 glycosylated Asn resi dues. The unglycosylated protein has a MW of 64,245-KDa and a pl of 4. 97. Two putative metal binding sites were identified in the molecule. This enzyme may represent a special class of high molecular weight aci d phosphatase, since it lacks the active site sequence RHGXRXP and sho ws no significant homology with known acid phosphatases containing thi s active site. Homology to human type 5 and A.niger APases was detecte d, however. (C) 1994 Academic Press, Inc.