Comparison of two glucoamylases from Hormoconis resinae.
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.
Fagerström
R
R
Research Laboratories, Alko Ltd, Helsinki, Finland.
Vainio
A
A
Suoranta
K
K
Pakula
T
T
Kalkkinen
N
N
Torkkeli
H
H
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D002963:Cladosporium / Q000201:enzymology* / Q000235:genetics; D005087:Glucan 1,4-alpha-Glucosidase / Q000235:genetics / Q000302:isolation & purification*; D006863:Hydrogen-Ion Concentration; D003904:Mitosporic Fungi / Q000201:enzymology*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D012689:Sequence Homology, Nucleic Acid; D013696:Temperature
D000596:Amino Acids; D005087:Glucan 1,4-alpha-Glucosidase