1. Comparison of two glucoamylases from Hormoconis resinae.
- Author
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Fagerström R, Vainio A, Suoranta K, Pakula T, Kalkkinen N, and Torkkeli H
- Subjects
- Amino Acid Sequence, Amino Acids analysis, Cladosporium genetics, Glucan 1,4-alpha-Glucosidase genetics, Hydrogen-Ion Concentration, Molecular Sequence Data, Molecular Weight, Sequence Homology, Nucleic Acid, Temperature, Cladosporium enzymology, Glucan 1,4-alpha-Glucosidase isolation & purification, Mitosporic Fungi enzymology
- Abstract
Two extracellular glucoamylases (EC 3.2.1.3), glucoamylase P and glucoamylase S, were purified to homogeneity from the culture medium of Hormoconis resinae (ATCC 20495; formerly Cladosporium resinae) by a new method. Their apparent molecular masses (71 kDa glucoamylase P; 78 kDa glucoamylase S) and catalytic properties agreed well with those previously reported in the literature. Heat inactivation studies suggested that the high debranching (1,6-glycosidic) activity of glucoamylase P preparations (measured with pullulan) may reside in the same protein molecule as its 1,4-glycosidic activity (measured with soluble starch). Although glucoamylase S had virtually no debranching activity, it cross-reacted with polyclonal antibodies raised against glucoamylase P, and the two enzymes had very similar amino acid compositions. However, peptide mapping and amino-terminal sequencing studies of the peptides showed that the two enzymes have different sequences and must be encoded by different genes.
- Published
- 1990
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