AMINO-ACID-COMPOSITION AND N-TERMINAL SEQUENCE OF PURIFIED CYSTINE BINDING-PROTEIN OF ESCHERICHIA-COLI

Cystine Binding Protein (CBP), a commercially available crude protein extract obtained by osmotic shock of Escherichia coli (E. coli) , was studied to characterize further its cystine binding properties and to elucidate its cystine transport activity. We report here the amino acid composition, the N-terminal amino acid sequence analysis and some binding characteristics of the purified cystine binding component of CBP. A search of the Swiss-Prot version 20 data base revealed that this sequence is unique.