Transport of phenylalanine by conidia of Fusarium sulphureum.
L-Phenylalanine was actively transported by conidia of Fusarium sulphurenum Schlect (isolate 1). Uptake was optimal at pH 7, 30 degrees C; respiration-dependent; and was unaffected by relatively high internal concentrations of phenylalanine. The Km for transport was 1-3 X 10(-5) M and the Vmax was 2.5-4 nmol/min per milligram dry weight. Phenylalanine is transported by a general transport system for basic and neutral amino acids. Sucrose repressed uptake of phenylalanine and this repression was largely negated by cycloheximide. Efflux of accumulated phenylalanine was influx-dependent; this transport system deteriorated slowly with aging of the conidial culture.
D000596:Amino Acids / Q000378:metabolism; D001386:Azides / Q000494:pharmacology; D001693:Biological Transport, Active; D003486:Cyanides / Q000494:pharmacology; D003513:Cycloheximide / Q000494:pharmacology; D004140:Dinitrophenols / Q000494:pharmacology; D005033:Ethylmaleimide / Q000494:pharmacology; D005670:Fusarium / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D010101:Oxygen Consumption; D010649:Phenylalanine / Q000378:metabolism*; D013172:Spores, Fungal / Q000378:metabolism; D013696:Temperature
D000596:Amino Acids; D001386:Azides; D003486:Cyanides; D004140:Dinitrophenols; D010649:Phenylalanine; D003513:Cycloheximide; D005033:Ethylmaleimide