Assessment of binding of L-cystine and L-lysine by rat renal brush-border membranes

• Published in: Biochimica et biophysica acta Vol. 863; no. 2; p. 332
• Main Authors: Hsu, B Y, McNamara, P D, Rea, C T, Corcoran, S M, Segal, S
• Format: Journal Article
• Language: English
• Published: Netherlands 16-12-1986
• Subjects: Animals; Chemical Precipitation; Cystine - metabolism; Kidney - metabolism; Kinetics; Lysine - metabolism; Microvilli - metabolism; Osmolar Concentration; Rats; Trichloroacetic Acid
• ISSN: 0006-3002
• DOI: 10.1016/0005-2736(86)90277-4

Cystine and lysine bind to isolated rat renal brush-border vesicles. Three methods to determine the extent of amino acid binding to the membranes have been compared, one relying on the osmotic reactivity of the vesicle, a second by trichloroacetic acid precipitation of membrane-bound material and a third by initial rate analysis. For cystine, all methods yield comparable results at early time points, indicating the trichloroacetic acid method is a simple and valuable tool for binding estimation under initial-rate or near initial-rate conditions. For lysine, initial rate analysis and osmotic perturbation are the methods of choice since lysine co-precipitates with trichloroacetic acid.