This project has revealed that commercially obtained cystine binding protein of E. coli is heterogeneous. Purification gave four proteins. One protein bound cystine and was not similar to known proteins in data banks. Another protein was highly similar to a known histidine binding protein of S. typhimurium and can be used to specifically analyze tissues for histidine content as is now done for cystine. In other work, normal fibroblasts were shown to be reversibly induced by hydrophobic amines and certain steroids to mimic NPC disease. The development of this disease and subsequent restoration to normal can now be studied using known agonists and antagonists of intracellular lipid transport and metabolism. Trafficking of intracellular cholesterol may be via the golgi. It was also demonstrated that normal and cystinotic fibroblasts have two ascorbic acid transporters, a high affinity Na+ dependent transporter and a low affinity Na+ independent transporter, neither of which is due to diffusion. The transporters are not different in the two types of cells.
