Reports

Cystine transport is defective in isolated leukocyte lysosomes from patients with cystinosis

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Science  24 Sep 1982:
Vol. 217, Issue 4566, pp. 1263-1265
DOI: 10.1126/science.7112129

Abstract

The activity of a cystine transport system in lysosomes prepared from the leukocytes of patients with cystinosis was found to be deficient. In normal subjects, this system was resistant to N-ethylmaleimide and demonstrated saturation kinetics. Lysosomes from individuals heterozygous for cystinosis demonstrated a reduced maximum velocity for cystine egress from lysosomes. The rate of cystine escape from normal lysosomes was enhanced by adenosine triphosphate. The availability of normal and mutant lysosomes provides a means of investigating mechanisms of amino acid transport across lysosomal membranes.