Glycine transport by cultured human fibroblasts

• Published in: Biochemical and biophysical research communications Vol. 152; no. 2; pp. 617 - 622
• Main Authors: Longo, Nicola, Franchi-Gazzola, Renata, Bussolati, Ovidio, Dall'Asta, Valeria, Nucci, Franca A., Spisni, Alberto, Gazzola, Gian C.
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 29.04.1988; Elsevier
• Subjects: Adult; Aminoisobutyric Acids - pharmacology; Analytical, structural and metabolic biochemistry; Biological and medical sciences; Biological Transport - drug effects; Cells, Cultured; Culture Media; Cycloheximide - pharmacology; fibroblasts; Fibroblasts - metabolism; Fundamental and applied biological sciences. Psychology; glycine; Glycine - metabolism; Humans; Kinetics; man; Proteins; MeAIB; EBSS; FBS
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/S0006-291X(88)80083-4

The transport of glycine was studied in cultured human fibroblasts. The amino acid entered the cell by Na +-dependent and Na +-independent mechanisms. Na +-independent glycine (0.1 mM) transport was less than 10% of total uptake and occurred by a mechanism formally indistinguishable from diffusion. Two distinct routes contributed to Na +-dependent glycine transport. The first route was identified with system A because it was inhibited by MeAIB and underwent adaptive regulation. The second route was identified with system ASC as it was inhibited by L-alanine, but not by MeAIB. Kinetic analysis revealed that the two systems operated glycine transport with the same Km of 1.6 mM, a value unusually high for system ASC.