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Evidence that cleavage of the precursor enzyme by autocatalysis caused secretion of multiple amylases by Aspergillus niger
Author(s) -
Ravi-Kumar K,
Venkatesh K.S,
Umesh-Kumar S
Publication year - 2004
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(03)01510-2
Subject(s) - aspergillus niger , secretion , cleavage (geology) , amylase , enzyme , chemistry , autocatalysis , biochemistry , aspergillus , biology , microbiology and biotechnology , catalysis , paleontology , fracture (geology)
The observation that a mutant strain of Aspergillus niger isolated for protease overproduction accumulated Taka‐amylase supported an earlier report that processing of the precursor amylase by protease resulted in the secretion of multiple amylases. Studies using a mutant strain revealed that such processing was not due to aspergillopepsin but to autocatalysis by an inherent protease activity of the precursor and glucoamylase. Alignment of protease sequences with glucoamylase showed regions of consensus with serine carboxypeptidase of A. niger . Thus point mutations in this region due to ultraviolet radiation apparently caused the mutant to evolve with enhanced protease activity that degraded the precursor and accumulated Taka‐amylase.