Influence of exo beta-D-galactofuranosidase inhibitors in cultures of Penicillium fellutanum and modifications in hyphal cell structure.
We have examined beta-D-galactofuranosidase production by Penicillium fellutanum in the presence of D-galactono-1,4-lactone or 4-aminophenyl 1-thio-beta-D-galactofuranoside, two potent in vitro inhibitors of the enzyme. Activity of the enzyme in the culture filtrate was increased by 35% when glucose was replaced by D-galactose as the carbon source, and the activity diminished 80% of the control value when the inhibitors were added. Significant alterations of the culture were observed: (a) the medium became increasingly opalescent due to the secretion of a protein aggregate (PA) which contained 15% neutral sugar, mainly ribose; (b) the peptidophosphogalactomannan (pPGM) containing galactofuranose, normally produced by P. fellutanum, could not be obtained from the culture medium in the presence of the inhibitors; (c) the content of galactofuranose in the cell wall was significantly decreased in the presence of D-galactono-1,4-lactone. The influence on the mycelia growth was investigated by light microscopy (LM) and transmission electron microscopy (TEM) showing important alterations.
Mariño
Karina
K
CIHIDECAR, Departamento de Química Orgánica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellón II, Ciudad Universitaria, 1428, Buenos Aires, Argentina.
Lima
Carlos
C
Maldonado
Sara
S
Marino
Carla
C
de Lederkremer
Rosa M
RM
D002473:Cell Wall / Q000737:chemistry / Q000187:drug effects / Q000648:ultrastructure; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005690:Galactose / Q000378:metabolism; D006026:Glycoside Hydrolases; D025301:Hyphae / Q000737:chemistry / Q000187:drug effects* / Q000648:ultrastructure; D008854:Microscopy, Electron; D010407:Penicillium / Q000737:chemistry / Q000166:cytology* / Q000187:drug effects* / Q000648:ultrastructure; D001616:beta-Galactosidase / Q000037:antagonists & inhibitors* / Q000378:metabolism
D004791:Enzyme Inhibitors; D006026:Glycoside Hydrolases; C023112:exo-beta-D-galactofuranosidase; D001616:beta-Galactosidase; D005690:Galactose